The efficacy of drying on the microbial disinfection of hemp biomass needs to be studied

Posted on August 18, 2022 by hemp2022

Based on their molecular structures and compositions,terpenes are high non-polar molecules,and have very low solubility in aqueous solution.In addition,they are in general highly volatile,and each terpene has its unique aroma.Some typical terpene compounds found in the hemp,their aroma characteristics and alternative sources are shown in Fig.4B.The typical boiling point of terpenes ranged from 119 °C to 198 °C.The terpenes are also not thermally stable and are susceptible to be oxidized into terpenoids.Conventionally,terpenes are usually used in cosmeceuticals,perfumes and aroma therapy.Recent studies have shown that terpenes in the hemp may play an important role in the ‘entourage effects’,that is ‘1 + 0 > 1’,of the medicinal properties and functionalities of the CBD.Such a phytocannabinoid-terpenoid synergy could enhance the treatment effectiveness of inflammation,pain,anxiety,and infections.Additionally,the therapeutic and pharmaceutical values,and functionality of terpenes themselves are usually underestimated.For example,myrcene is a potent analgesic,and has great antioxidant and anti-inflammatory activities; Limonene shows good antiviral,anti-bacteria and antidiabetic properties; Pinene has memory improvement,anti-inflammatory and antimicrobial functions ; Linalool shows sedative,anti-influenza,antimicrobial and neuroprotective effects; Caryophyllene is an excellent analgesic agent and antispasmic in muscles.It is worthy of mentioning that terpenes are GRAS additives approved by FDA,which means they can be used in food and beverages as flavor or nutrient supplements.Due to their abundance in the plant,hemp terpenes are promising sources of future functional food ingredients.Together with the booming business of CBD,terpenes are also drawing more and more interest in both food industry and academia.However,application of hemp terpenes is not easy due to their highly volatile and thermally unstable nature.

Particularly,they tend to evaporate and oxidize during the processing stages of the hemp plants,rolling benches canada such as drying,decarboxylation and extraction,and suffers significant loss.In fact,most of the terpene aroma in the currently available hemp products should offer additional value.More research needs to be done to collect the terpenes that are lost during the processing.Similar to CBD,how to improve the solubility,stability and bio-accessibility of terpenes in different food and beverage systems are also the key questions to be answered to determine the feasibility of using hemp terpenes as a future functional food ingredient.Furthermore,the interactions between each terpene species and CBD and the role of them in the ‘entourage effect’ are still not clear,and need to be better understood.Some cigarette and vape consumers claimed that they prefer the aroma of certain terpene species.Therefore,it is foreseen that exploration in adding certain types of high quality,food-safe hemp terpenes in foods accurately to reconstruct or create new terpene profiles in favor of consumers’ preference will be important and will deliver a more consumer friendly experience.At harvest,floral industrial hemp plants have high initial MCs.Chen et al.found the initial MCs of 3 California varieties were around 78% on wet basis.Before harvesting,plants usually have good defense mechanisms against microbial spoilage.However,after detached from the plant,the high moisture makes them susceptible to rapid quality deterioration and microbial spoilage.Therefore,successful additions of hemp CBD and terpenes in foods rely heavily on the preservation of these bio-active compounds and microbial safety of the hemp biomass and avoiding product loss via suitable processing.In addition,efficient and green extraction of these substances are critical.Likewise,the processing cost plays an important role in determining the pricing of CBD products.This section reviews and discusses the current status and recent advance in the drying,extraction and purification technologies for hemp in research and productions.The high MC of hemp at harvest makes them vulnerable to microbial spoilage during storage and is not desirable for downstream processing such as extraction and purification,thus the fresh floral hemp needs to be dried efficiently.At present,the harvested hemp is dried indoor in the industry by using two methods: hang-drying and tray drying.In the hang-drying scenario,the entire hemp plants are hung upside down on wires in a well-ventilated drying facility ,where the temperature is commonly 15‒21 °C,and relative humidity is 55%‒65%.In such a configuration,the stalks and branches of hemp plant droop are down and form a ‘closing umbrella’ structure,where the outer parts cover the center part of the plants.Since the hang-drying is normally conducted under natural convection conditions,the airflow is relatively weak,which leads to slow convective heat and moisture transfer rate and low penetration into the center.As a result,moisture in the center part cannot be effectively removed,and the hemp plant is not uniformly dried.

Mold and mildew may then grow in the center,and the quality of the dried hemp is not uniform.The hang-drying process usually takes 7‒10 days to finish and has high labor cost.Since CBD and terpenes reside mainly in the ‘cola’ of the hemp,drying the stalk and stems causes energy waste and is not necessary.Tray drying is an ‘upgrade’ method to the hang-drying.As shown in Fig.5C,colas are detached from the plant and placed in thin layers on drying trays and dried indoor under similar conditions as the hang-drying.Challa et al.found that tray drying is faster than hang-drying,but the drying rate is still relatively low,requiring 3‒5 days to dry the moisture down to a safe level for storage.Due to the high production yield and increasing cultivation,a larger amount of harvested hemp will need to be dried in a short season,and the currently applied low efficient drying methods may not fulfill the needs.Novel efficient mechanical drying technologies are thus needed to improve the processing efficiency,moisture uniformity,quality and safety of the products.Hot air drying is one of the most commonly used technology for foods and agricultural products due to their advantages of easy implementation,low operating cost and availability of equipment in the industry.The heat and moisture transfer rates during the drying process are significantly improved with the forced convection under HA drying compared to the natural air drying.However,it should be noted that thermally drying the hemp may result in vaporization of terpenes due to their volatile nature and degradation of terpenes and cannabinoids.Chen et al.studied the drying characteristics of hemp inflorescence and leaves under HA drying at different temperatures and found the drying time was significantly reduced compared with ambient air drying.Meanwhile,it was found that drying temperature did not have significant influence on the CBD contents in the hemp biomass,but increasing the temperature caused significant loss of terpenes.It was also found that increasing the drying temperature facilitated the conversion of CBDA to CBD.Similarly,Challa found increasing the HA temperature above 40 °C did not significantly affect the CBD contents in hemp,and non-isothermal HA drying led to the 90% drying time reduction compared to the control condition.Chasiotis et al.found that increasing the drying temperature from 40 °C to 60 °C and applying a nonisothermal drying regime increased the CBD and Δ9 -THC levels in cannabis inflorescence and leaves.Metin Ozguven et al.applied HA drying with a stepwise change temperature for peppermints and found using a lower temperature HA in the first 4 h and then raised to 55 °C to finish the drying could reduce the drying time while retaining the desired product quality.Zotti-Sperotto et al.applied intermittent HA drying to Lippia origanoides HBK leaves and Schinus terebinthifolius Raddi fruits,and found intermittent drying led to increased essential oil and thymol yield of L.origanoides without significantly affecting the color and quality attributes.

In addition,previous studies have shown that non-isothermal drying can improve the energy efficiency,achieve effective disinfection,disinfestation and enzymatic deactivation of foods and agricultural products.More research is needed in studying the efficacy of non-isothermal HA drying on the efficacy of disinfection and enzymatic deactivation of hemp biomass.Infrared drying is another promising drying technology that has been used for foods and plants.Due to the intensive transfer by thermal radiation,IR drying is particularly efficient for drying of thin materials or surface pre-drying of thick materials.Far-IR can penetrate 2‒5 mm into the surface of foods and generates strong thermal effects via vibrations of water molecules.IR drying has been successfully used for different herbs that contain valuable bio-active compounds.Nadee et al.found that IR drying was faster than HA drying and more energy efficient,while maintaining similar product qualities of Pandanus tea leaf.Xie et al.suggested that IR heating is suitable for the efficient drying and quality preservation of Chinese and Indian medicinal herbs.However,there were also studies that reported that IR drying led to non-uniform drying and uneven moisture distribution in herbs,as well as significant loss of color,aroma and bio-active compounds.Freeze drying is considered to have minor effects on the volatile and bioactive compounds in plants,which should be attributed to the very low temperature and low oxygen availability during the freeze drying conditions.Chen et al.found that freeze drying led to much less terpene loss than the HA drying.However,freeze drying is usually time consuming and energy intensive.Chimsook studied the drying characteristics,antioxidant activity and total phenolic contents of Cordyceps militaris for cordycepin production by freeze drying and HA drying.It was found that freeze drying led to higher retention of phenolics and antioxidant activity,but HA drying had much lower operating costs.Dielectric drying,including microwave and radio frequency drying,can penetrate the objects and generate volumetric heating,which is beneficial for improving the drying efficiency,reduces energy consumption and preserves of sensitive volatile and bio-active compounds.Rehkopf developed a RF drying technology to rapidly dry cannabis,prevent the microbial spoilage and retain the product quality.MW and RF have also been applied to assist other drying technologies to improve the drying efficiency and preserve bio-active compounds.Durance et al.developed a patent on a rapid drying technology for marijuana using MW-assisted vacuum drying,which has been commercialized by EnWave Technologies.Other combined drying technologies have also been studied for efficient drying different types of foods and agricultural products,such as MW-assisted HA drying,ultrasound-assisted HA drying,steam-assisted HA impingement drying,IR-assisted vacuum drying,and sequential IR and HA drying.The feasibility of these technologies for hemp drying and preservation of CBD and terpenes remains to be investigated.Currently,flood table research on developing efficient drying technologies for hemp,and on the influence of different drying methods on the retention of CBD and terpenes is scarce in the literature.The suitable drying methods and drying conditions may be tailored to the requirements of the final products and consumers’ needs.

The feasibility of different drying technologies for commercial scale hemp production will need to be evaluated by conducting techno-economic analysis.It will be important to study the potential measures to recover and collect the terpenes that are lost by vaporization during the processing.Currently,there are two major extraction methods that are widely used in the hemp industry: solvent extraction and super-critical fluid extraction.The purpose of extraction from plant materials is to obtain as much of the desired substances as possible,meanwhile,to minimize the co-extraction of undesired substances.It is noticed that besides cannabinoids and terpenes,hemp biomass is also rich in fatty acids and other minor substances such as chlorophyll,phenolics and flavonoids.Due to the lipophilic nature of both CBD and terpenes,they are usually co-extracted along with the lipids.Therefore,selection of suitable extraction methods with high yield and selectivity is very important.Additionally,food safety is one of the most important factors to be considered in the solvent selection for food applications.Solvent extraction is one of the most commonly used methods for plant extraction industry.This is the process involving the solid-liquid maceration with different solvents.In general,there are two major types of solvents that are mostly used in the industry: ethanol and hydrocarbons.Ethanol is a polar solvent,which usually has a higher throughput and extraction yield compared to other methods and is able to obtain full-spectrum distillate easily.Since ethanol is a GRAS solvent according to FDA,the food safety of ethanol extracts is not a concern.Meanwhile,due to the hydrophilic nature,ethanol extraction usually leads to less co-extraction of lipids and wax from the hemp biomass,and thus winterization and dewaxing could be avoided or even eliminated.However,its selectivity to cannabinoids and terpenes is usually low.Disadvantages of this method include harder post-separation and purification,low selectivity,large solvent loss,difficult solvent recovery and large solvent cost.Moreover,ethanol is very flammable and has fire safety risk.Hydrocarbon extraction is usually performed with butane,hexane,heptane,etc.,which are typical non-polar solvents.The extraction efficiency with hydrocarbon is usually higher than ethanol extraction,and the solvent recovery is much easier than ethanol,and thus the solvent cost with hydrocarbon should be cheaper.Due to their highly non-polar nature,hydrocarbon extraction can retain more terpenes than ethanol,but also co-extract the lipids and wax from the plants,thus winterization is necessary.In recent years,the use of hydrocarbons,particularly hexane,has rising concerns,as they may potentially cause concerns to human health.The United States Environmental Protection Agency indicates that ‘acute inhalation exposure of humans to high levels of hexane causes mild central nervous system effects’.Similar to ethanol,hydrocarbons are also flammable and have the fire safety risk during operations.In addition,emission of hydrocarbons contributes to the global warming and environmental impacts.

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Members of the hemp group reported higher levels of trait food neophobia than the non-hemp group

Posted on August 17, 2022 by hemp2022

Hemp as a food source was unavailable in Australia prior to the change in legislation in November 2017.Hemp’s rich history combined with the recent change in legal status has provided an ideal exemplar to evaluate the introduction of a unique novel food into the Australian consumer market.This study aims to understand which factors contribute to the early adoption of hemp by comparing attributes of individuals who have consumed hemp food to those who have chosen not to,one year after its introduction to the Australian market.The process of diffusion of a product throughout a population becomes an underlying factor in our understanding of the acceptance of novel food products.Rogers’ application of diffusion of innovation in new product acceptance,and its subsequent redefinition ,remains a widely accepted framework for acceptance of novel products throughout a population.diffusion is reported to be determined by “a chain of influence from the earlier adoption groups to the later adoption groups” ,therefore placing importance on understanding group differences not only in the early adoption of a product,but also in predicting where group influence from early adopters to later adoptees becomes an instrumental part of the diffusion process.The current study sought to evaluate group differences between hemp food consumer groups at an early point after its introduction to the Australian market in order to help define the factors integral to the diffusion process.diffusion of a novel product does not occur in isolation but within a broader context of policy,structure,and systems.However,understanding the motivations of consumers to adopt a product and how perception differs between adoption groups provides insight to the trajectory of a novel product within this system.Each adoption group is defined according to where in the diffusion process a consumer first uses a novel product,and are shown in Fig.1.Each group display characteristics common among its members that cumulatively influence their perception and attitude toward a novel product,with these characteristics occurring within a whole population in a normal distribution,as would be expected of behavioural and personality traits.

Innovators and early adopters share some attributes that result in their having early product knowledge,be open to innovation,microgreen rack for sale and serve as role models within the diffusion process to trigger further adoption in others.In contrast,adoption by early and late majority groups is largely due to peer pressure,and laggards are the last within a social system to adopt a novel product,needing reassurance of a product’s worth and knowledge of the product that alleviates suspicion of it before final acceptance.Non-adopters are considered separate to the adopter groups under the diffusion model and are those consumers whose traits contribute to a value judgement of how beneficial the novel product is to them,and who decide that there are insufficient benefits to its adoption.While non-adopters will never take up the novel product,there will be stages throughout the diffusion process defined by where consumers who will ultimately become adopters have not yet accepted the novel product.During this time,understanding the attributes of each of the groups and the sequential nature of the process might help define where along the adoption continuum time line the acceptance of a product currently sits.More recent models of diffusion of novel products incorporate feedback loops to define the social factors influencing product adoption and while it is beyond the scope of this paper to evaluate the dynamics of social influence on product adoption,it is important to mention that this model continues to place importance on path dependence of the process,particularly the need to understand the attributes of each of the adoption groups within the sequential diffusion process.For clarity of definition between the theorised and study sample groups,the study cohorts will be described in this paper as hemp group and non-hemp group,and Rogers’ innovation groups referred to by their empirically reported names as demonstrated in Fig.1.The hemp group are defined as those study participants who reported having consumed hemp food at the time of the study,and the non-hemp group are defined as those study participants who reported knowing that hemp food had been legalised,knew of a place that hemp food was sold,and had not at the time of the study consumed hemp food.It was anticipated that the hemp group would comprise mostly early adopters as well as some early majority adopter members,and that the non-hemp group would largely comprise those who would remain non-adopters but may also include some early and late majority adopters and laggards who had not yet made the decision to consume but would do so at some time in the future.

Non-hemp group members who reported not knowing a place where hemp food could be purchased were excluded from the study.It was anticipated that understanding the predicted trajectory of the diffusion process might reap benefits for the hemp food industry,and provide insight into the diffusion of a novel food product in the Australian population.Intrinsic to the diffusion process is the compatibility of the novel product to the belief systems,needs and values of consumers adopting the product.The rate and degree of diffusion of a novel product is reported to occur throughout a population according to these factors,including specific value judgements of potential adoptees,and their amenability to certain external effects,including product promotion and price.The Food Choice Questionnaire has been empirically demonstrated to be a reliable and valid measure of several of the factors that impact on these value judgements and was adopted as a measure of these factors in the current study.Food neophobia is often considered to be the greatest barrier to acceptance of novel foods.Food neophobia,literally meaning a fear of new food,is considered an enduring personality trait of evolutionary origins which can be conceptualised as the avoidance factor along a “neophobia-neophilia continuum” according to con-sumers’ propensity to avoid novel foods,or be drawn toward them.It has been consistently found to be not only a significant barrier to the acceptance of novel food ,but also a barrier to dietary change,particularly where behavioural modification is needed to address diet related health problems,and has been demonstrated to be associated more generally with reduced dietary varietal intake.Food neophobia has been reported to be inversely related to food satisfaction,as well as more generally to life satisfaction.According to Rogers’ description of adopter groups,“laggards tend to be suspicious of innovation and change agents”,with any adoption of novel products “lagging far behind awareness-knowledge” of the novel products.The highest rates of food neophobia would be expected to be reported by both laggards,and those consumers whose aversion contributes to their choice to never consume the food,the non-hemp group.It was hypothesised that the avoidance of hemp food demonstrated by the non-hemp group in the current study was largely representative of trait food neophobia,and that this group would score higher in the FNS than the hemp consumers.

Factors contributing to food choice behaviour are drawn from evolutionary survival needs,neuropsychological processes in response to sensory input,biological and learned responses,and a myriad of sociocultural influences.Vabo and Hansen reported from a broad review of consumer marketing and food science literature that while many factors contributed similarly to both food choice and food preference,there were many facets of food choice that were distinct from food preference.Where preference for foods is largely developed early in life,much of it in the first five years,food choice is a dynamic phenomenon which can change along with situational and personal changes.Additionally,socially constructed associations based on previous experience and beliefs can influence consumers’ evaluation of food in the marketplace.These dynamics of food choice may apply to hemp foods where,for example,an association with hemp’s illegal cousin,marijuana,might negatively impact acceptance.Rasco reported a similar phenomenon where consumer perceptions toward specific aquatic foods were detrimentally affected by negative associations made to mercury,drug residue,and environmental contaminants through the actions of activists.While consumer concerns were reported to be unfounded,it was clear that negative consumer perceptions had a negative impact on fish consumption.Therefore,despite many similarities with other novel foods the association hemp has with marijuana,or more specifically with tetrahydrocannabinol ,creates a unique circumstance which should be evaluated in conjunction with hemp food acceptance.It was hypothesised that in a similar way that consumer perceptions of aquatic foods was impacted through negative associations,the association of hemp food with marijuana would impact the acceptance of hemp food.Additional factors considered to be influential in the dynamics of food choice include those measured by the Food Choice Questionnaire.Since its inception,the FCQ has been employed within a multitude of contexts evaluating the acceptance of novel foods.Adopting a shortened version of the FCQ,Annunziata et al.found price,convenience,health concerns,and suspicion of reliability of product information contributed to negative attitudes toward functional foods for older consumers.Jaeger et al.found health,mood,convenience,and sensory appeal were more important considerations for New Zealand consumers than natural content,price,cannabis grow facility layout and weight control across a variety of foods,and that familiarity increased in importance for consumers high in food neophobia.Schlup and Brunner found health and convenience have significant positive relationships with a willingness to consume a novel food,insects,while a higher importance placed on familiarity meant that consumers were inclined to prefer more familiar products,resulting in a significant negative relationship with willingness to consume the insects.

Findings from several studies ,each employing the FCQ to determine factors influencing novel food acceptance,support the suitability of the measure in determining differences in food choice priorities between the hemp and non-hemp groups.It was hypothesised that a higher priority placed by the non-hemp group on factors contributing to food choice might indicate greater complexity in the decision to consume,a notion supported in the literature where it was reported there is an increase in complexity of the decision making process as food neophobia increased.The anticipated capture of late adopters and laggards within the non-hemp group was expected to contribute to an overall higher level of food neophobia for that group.It was expected that eight constructs have a static relationship to choice for each individual throughout the diffusion model.In contrast,price,acts in a different way as its influence is fluid,differing in importance according to the current status of the diffusion of the novel product rather than the attributes of the product itself.Socioeconomic factors are determined to play an important role in the adoption decision early in the diffusion process but have a much lesser impact later in the diffusion process when pressure of social norms cause economic considerations to be placed aside,adding to the complexity of the decision making process.The notion of increased complexity in decision making for individuals reluctant to accept novel foods is supported by a means-end-chain methodology evaluation of the emotional influence on purchase behaviour toward novel foods.The relationship of food choice motivation with complexity in the decision making process leads to a prediction that factors measured by the FCQ will have a higher reported importance in the current study for those consumers less willing to consume the novel food,the non-hemp consumers’ group members.The current study sought to define differences between individuals who had consumed hemp and those who had not,one year after its legalisation,with the aim of understanding differences in motivation toward adoption of a novel product,hemp food.Using Rogers’ model of diffusion of a novel product throughout a population,it was firstly hypothesised that trait food neophobia would contribute to the non-adoption of hemp food,demonstrated by a higher score on the food neophobia scale for the non-hemp group.While a difference was reported between the groups,it was not in the direction expected.Rogers’ outline of attributes for adoption groups leads to a suggestion that the unexpected inverse direction of the difference between the study cohorts might indicate that laggards have been captured in the hemp group which was thought to be comprised primarily of the early adopters of hemp food.Food neophobia is expected to correlate with suspicion of a novel product and avoidance behaviour as would be expected to be displayed by laggards and non-adopters.While there is no standardised time frame for diffusion of a novel product throughout a population and variation between similar products can be several decades ,the finding of higher food neophobia in those who have already consumed hemp food suggests the hemp group has captured a greater diversity of consumers than merely the early adopters.One conclusion that might be drawn from this is that diffusion of hemp food has reached a later stage than was anticipated prior to the study.

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Protein digestibility can be affected by the nature and structural arrangement of protein in the seed

Posted on August 16, 2022 by hemp2022

Their study showed that hemp hulls had a significant impact on protein digestibility,with dehulled hemp seed having a PDCAAS score of 61%,whereas whole seeds had a score of 51%.This finding could mean that whole seed from hemp lines such as Frog-1 and ECO_50 GC,with high heart %,could have higher protein digestibility,than other lines with similar protein content,but lower heart %.Other possible factors that affect digestibility need to be considered,and these can be evaluated in the future.We demonstrate that the protein is present as protein bodies throughout the seed.To our knowledge this has not been shown before,but is consistent with seed from other dicotyledonous plants.The structure of protein bodies in monocotyledonous seed such as sorghum are known to be formed due to the interaction of several proteins with a hydrophobic protein on the surface of the body.γ-kaffrin is responsible for creating the stable structure of sorghum protein bodies and may impede digestibility.There is no data on the arrangement of the seed storage proteins within hemp seed,but a recent paper has revealed that the C.sativa genome contains six 11S edestin genes,two 2S albumin genes and one 7S vicilin-like gene.There is likely to be variation in the levels of hemp seed storage proteins between genotypes and with environmental conditions which may in turn affect both protein digestibility and the amount of the most limiting amino acid,Lys.A subset of the most promising lines could be analyzed in the future to reveal the extent of genetic variability for specific proteins and bio-availability of Lys.Strong environment and G x E effects on protein content have been shown,P < 0.0001 and P ¼ 0.0019 respectively in a Canadian field trial with 11 lines,although a relatively low CV was obtained for protein in the 20 hemp lines grown in Australia.In the Canadian field trial,the average protein yield for Midlands X,Midlands S and Ferimon 12 ranked 2nd,6th and 7th,with the highest average protein yielding line being FINOLA,at 25.7%,compared to Midlands X,Midlands S and Ferimon 12 at 25.2%,23.8% and 23.0% respectively.In the data reported here,from a single batch of seed,three lines,Ferimon 12,ECO_222 and ECO_208 had highest protein levels at 26.9%,26.2% and 25.9% respectively.Studies in other crops suggest that stress can reduce seed protein content and also change the relative abundance of different storage proteins and amino acid profiles.The relative susceptibility of hemp protein levels and amino acid profiles to environmental factors including heat will be an important area for future selection of hemp lines for food.

The 20 hemp lines analyzed in this study had a greater range of total lipid content,with a higher maximum value of 37.8% ,vertical hydroponic system compared to 34.8% and 30.6% in previous reports.Two of the lines in each of the other studies were also analyzed in this study,Midlands X and Midlands S had slightly higher total lipids in the current study  compared to the 2015 report where both lines had 29.5% total lipid.A similar small difference was observed for KC Dora and the 2016 study with 31.5% total lipid,however there was a greater different for Ferimon 12 which had the highest total lipid content in this study at 37.8%,but only 30.2% in Galasso et al..The mean values of the individual lipids are also similar between this study,and the other two studies,with no notable differences.The main benefit of analyzing the individual lipids is to calculate the ratio of omega-6 to omega-3 fatty acids ,which is generally around 3:1 for hemp seed.For example,the twenty lines reported by Galasso and colleagues had a mean LA:ALA ratio of 3.32.Only a single line,CAN24 had a dramatically reduced ratio at 1.63,with the next lowest ratio at 2.63 and another three other lines had a ratio  3.The data reported here revealed that eight lines had LA: ALA  3,with two lines close to 2 and Han-NE.This ratio provides new plant lines to consider in breeding programs to further improve this trait.Lastly,we discuss phytate levels in the 20 hemp lines.Phytate levels in hemp are similar to other oil seeds,most notably,linseed where they range from 2.15 to 3.69 g/100 g.We found three prior hemp studies that measured phytate.The first study obtained a mean value almost 2-fold higher than current study even after taking into account they used defatted flour rather than whole seeds,but the second study had more comparable values at 3.5  0.2 g/100 g.The values reported in our study likely represent real values,as the kit provided oat flour controls gave the expected values,and recovery of total P was as expected for a mixed oat plus hemp control assay compared to the two samples processed individually.Furthermore the mean value reported here of 2.67  0.43 g/100 g is consistent with the value obtained for whole hemp send with a recently “improved” method of phytate determination,of 2.75 g/100 g.Despite the differences in absolute values between this study and Galasso,the samples showed the same trends,with KC Dora having the lowest levels of phytate and Fermion 12 having higher,above average levels of phytate.Phytate is often considered an antinutrient because it can bind/ chelate other nutrients,especially divalent cations ,and affects the bioavailability of micronutrients such as Zn and digestibility of proteins.Another potential negative of high phytate levels is the positive correlation with trypsin inhibitor.This could potentially affect the availability of protein in raw foods,but is not an issue in cooked food.

Phytate does have some positive attributes for human health.It has antioxidant properties and this may in part account for observed anti-cancer activities in,for example,rat studies where pure phytic acid is more efficient at reducing the incidence and growth of mammary tumours compared to all bran.In summary,the new research presented fills some previous knowledge gaps,most significantly providing details on the nature of the major dietary fiber components of hemp seed.The use of antibodies revealed a high level of diversity of polysaccharides and some cell-type specificity for the different plant cell wall polymers.Cellulose and xylan were identifified as the major components of hemp hulls,and hemp hearts contain low levels of starch.The findings contribute to efforts to grow the global hemp industry,especially for food use and to improve human nutrition.Future research into consumer traits is needed,especially in the area of flavour characteristics and new product development.For example,different hemp lines can have different flavour profiles and new products include microgreens,which are excellent ways to reduce anti-nutrients such as phytate and increase antioxidants.With growing worldwide interest in hemp as a more sustainable crop,the breadth of traits incorporated into breeding programs is expected to grow,accelerating the improvement of hemp for consumers and human nutrition.Dispersion of heavy metals in soils is an age-old problem deriving from both natural and anthropic sources.Among the anthropic contribution to soil contamination by metals,land application of treated wastewater,sewage sludge,fertilizers,and industrial activities are major concerns.Unbalanced amounts of heavy metals may cause perturbation of soil parameters with consequent toxic effects on plants,in the nearby water supplies,and,ultimately,in the whole food chain.Typically,elements,such as copper ,nickel ,zinc ,and chromium are biologically essential for plant growth but become toxic for animals and plants when their concentrations exceed certain threshold levels.Other heavy metals often found in contaminated soils,such as cadmium and lead are not essential for plants growth,and many studies associated their presence with neurological and endocrinological toxicity for humans along with carcinogenic effects.Since heavy metals are not biodegradable,they tend to accumulate in the environment becoming a high risk for biota over several years after their introduction in an ecosystem.The search for new solutions that can remediate heavy metals-contaminated soil is a critical prerequisite for the sustainable development of agriculture ,thus representing a topic of paramount importance.

The most consolidated strategies to remediate heavy-metals contaminated soils include physical and chemical approaches,like isolation,through capping and subsurface barriers; immobilization,by solidification/stabilization,vitrification,and chemical treatment; physical separation; extraction,by soil washing,pyrometallurgical extraction,in situ soil flushing,and electrokinetic treatment.Alternative approaches are gaining great attention as they combine cost-effectiveness,sustainability,low toxicity,and mobility decrease.They include bioaccumulation,phytoremediation ,bioleaching,and biochemical processes,in which living organisms such as plants or microbes are used to clean an area from contaminants.In particular,phytoremediation is attracting the attention of the scientific community,since it has been demonstrated to be a costeffective solution for the remediation of contaminated sites,and,in the meanwhile,to be a feasible method for bio-fixation of CO2,resulting in highly sustainable technology.The ability to absorb heavy metals generally depends on the biomass produced as well as on the ability of the plant to accumulate and translocate heavy metals in its biomass.According to recent scientific literature,a good candidate for phytoremediation of heavy metals-contaminated soil is the hemp plant.Kompolti,also known as hemp,the non-psychoactive variety of Cannabis sativa L.,is an annual dioecious high yielding industrial crop,and it is mainly grown for its fibers and seeds and used for textiles,clothing,insulation,biodegradable plastics,food,animal feed,and bio-fuel production.Hemp possesses some characteristics that make it very suitable for phytoremediation,such as high biomass,long roots,and an industrial-favorable short life cycle of 180 days.Importantly,hemp demonstrated a strong capability to sequester heavy metals like cadmium,zinc,lead,nickel,copper,and chromium when are present in contaminated soil and water.Another attractive approach for the remediation of contaminated sites is the application of bioleaching technology which uses direct metabolism or by-products of microbial processes to uptake heavy metals adsorbed onto the soil surface and to transform them so that the elements can be extracted when water is filtered through.Bioleaching has several advantages over conventional physical and chemical strategies,such as low cost,environmental sustainability,low hazardous characteristics of waste/sludge,low energy demand,and absence of toxic chemicals.Besides,phycoremediation,which involves eukariotic algae and cyanobacteria in remediation processes,cannabis grow setup has been extensively applied to the treatment of wastewater.

Nevertheless,its application to the remediation of heavy metals contaminated sediments is less documented.Among the cyanobacteria,Arthrospira platensis possesses excellent chelating properties both towards heavy metals present in humans and towards those present in the soil,water,and sludge.The dried biomass of Arthrospira platensis is commonly known as spirulina and it finds many applications in agriculture as a plant growth promoter,enhancing the growth,increasing the yield,and speeding up the seed germination.Recently,the employment of this blue-green alga to uptake heavy metals in contaminated sites has been explored.The presence of a chloroplast-type ferredoxin in the active center has been reported as responsible for the chelating capability of Spirulina ,whereby its efficiency is affected by many physical and chemical factors such as initial metal concentration,dosage,adsorption time,temperature,and pH.The present study aimed at both exploring the ability of the unreported combined use of hemp and spirulina to uptake six selected heavy metals from artificially contaminated soil and investigating,under controlled plant growing conditions,their distribution into the plant tissues.Specifically,hemp was chosen as the main agent for biological remediation,and spirulina was added as an enhancer of both the plant growth and the translocation of heavy metals in the hemp.The application of a non-targeted Nuclear Magnetic Resonance approach combined with an estimation of the residual metals by Inductively Coupled Plasma Atomic Emission Spectroscopy into the cultivation soil and within the different tissues of the plant was applied in view of gathering useful information on the efficiency of the integrated hemp/spirulina system.Obtaining this information is crucial for the potential re-utilization of the hemp plant or shoots of it,after the phytoremediation stage,for alternative usages,like production of bio-materials for textile industry,constructions,and biofuel.Plants were constantly monitored until the harvest by recording three main morphometric parameters: plant height ,i.e.height of stem from ground to apex,the number of leaf stages,and drum diameter.The biomass of stem and leaf samples was determined upon lyophilization; the sum of the biomass of the stem and leaf samples collected from the same plant was computed too and here referred to as “plant biomass”.The residual amount of heavy metals contained in leaves,stems,and soil after the harvest was measured; for each plant,also the sum of the heavy metal content of leaves plus stems was calculated.The shoots of plants were collected and transferred in refrigerated packaging with dry ice from the greenhouse to laboratories for further analyses.Samples of soil from each pot were collected after harvesting and kept in plastic bags at room temperature until analysis.Leaves and flowers were separated from stems and both portions of the plant were firstly freeze-dried at –50 ◦C and 0.180 mbar for 72 h in a lyophilizer.Then,the dried samples were mechanically ground in a blender,sieved through a mesh with a pore size of 0.5 mm,and stored at –20 ◦C until analysis.

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The hemp material is placed above 10 g of soil and a piece of cotton was added at the bottom of the funnel

Posted on August 15, 2022 by hemp2022

In this context, we recently studied a collection of environmental samples in Eastern France to determinate whether sawmills and market gardens , recognized as huge consumers of triazole molecules, were affected by the presence of azole-resistant A. fumigatus. The higher rate of resistant strains was found in market gardens, which mainly used difenoconazole as fungicide, available since 2008 in Europe . Thus, to reduce resistance, limiting the contact between A. fumigatus and triazole molecules clearly appears necessary, while maintaining their efficient action against phytopathogenic molds. Chemical treatments were recently proposed for the removal of pesticides present in wastewaters . To our knowledge, studies on their elimination in soils are however rare. An alternative would be to limit the difenoconazole diffusion in soils. For this, we studied the interaction of difenoconazole with a hemp-based material used as adsorbent. Hemp, an annual plant, is an interesting raw material due to its ease of production , low-cost and versatility. Hemp has numerous applications, e.g. textile and paper industries, building and insulation, cosmetics, food, and composites . However, applications in environmental chemistry are rare. Recently, hemp in fibre or felt forms has been proposed for metal removal from aqueous solutions . In this work, we propose for the first time the use of hemp to capture triazole fungicides before reaching soil. Studies concerning the effects of contact time, material dose, and difenoconazole concentration were evaluated using two analytical methods, i.e. batch method and percolation technique. The effect of organic content of soils was also investigated in order to confirm our previous hypothesis that more resistant strains in soils could be related with huge rate of organic matter . This could be explained by the stronger selection pressure exerted by fungicides more retained in soils containing high levels of organic matter .

The experiments were conducted using two adsorption-oriented methods: a batch method and a percolation technique. The first set of experiments was realized using a batch method detailed in previous works ,grow tent indoor for which kinetic and adsorption capacities of hemp were determined. For kinetic experiments, a hemp disk was added to 50 mL of the solution 12 in a tightly closed glass flask and stirred on a thermostatic mechanical shaker operating at 250 rpm for various times, ranging from 5 to 240 min. The experiments were conducted at 25.1C without changing the initial pH of the solution. For adsorption experiments, the effect of difenoconazole concentration and of disk mass was tested. Thus, 3 masses of hemp disk, i.e. 0.35 g , 0.70 g and 1.75 g , were added to 50 mL of solution S1 and solution S12 and stirred on a thermostatic mechanical shaker operating at 250 rpm during 15 min. Our objective was to demonstrate that the percentage of difenoconazole removal increased with the hemp dose, even for a low contact time . The removal of difenoconazole was expressed in percentage of abatement, representing the ratio between the amount of adsorbed difenoconazole and its initial amount. Experiments were performed in triplicate. The repeatability has been validated . For the percolation procedure, the system illustrated in Scheme 3 has been realized thanks to a funnel put on a flask to percolate solution 12 through the hemp. This technique is similar to an open column method. First, 50 mL of solution 12 was poured in the funnel onto 2 masses of hemp disk . The flow-through was collected after 1, 10 or 15 passes on the same hemp disk. Secondly, the same experiments were performed in presence of soils. 50 mL of solution 12 was then poured on the 3 types of soils with or without hemp disk.The removal of difenoconazole was also expressed in percentage of abatement/removal. To correct any adsorption of difenoconazole on container and cotton, control experiments were also carried out in the same conditions. Experiments were performed in triplicate. The pH of all solutions was measured before and after experiments.

It was noted during the experiments a slight pH variation did occur at the end of each experiment, i.e. an increase of between 0.2 and 0.3.The analytical methodology for the liquid-liquid extraction and quantification of difenoconazole is based on a method recently developed by our group . Ten milliliters of the solution after adsorption were added to 20 mL of acetonitrile and 3 g of NaCl and stirred by a magnetic plate for 10 min. The supernatant organic layers were recovered using a separating funnel and adjusted to 20 mL with acetonitrile. Then sample extracts were analyzed on a system composed of gas chromatography apparatus and a triple quadrupole spectrometer . The GC-MS/MS optimized parameters of the triazole studied are: precursor ion 265, product ion 202 and 139, collision energy 36 and 40 V, retention time 34.366 and 34.485 min, and limit of detection 0.28 μg/L. Soils of the percolation procedure have also been extracted for analysis. Ten grams of soil were added to 5 mL of water, 20 mL of acetonitrile and 3 g of NaCl, stirred by a vortex for 3 min. The supernatant organiclayers were recovered using centrifugation at 3500 x g for 5 min and adjusted to 20 mL with acetonitrile. Sample extracts were then analyzed as previously described . The portion of difenoconazole retained by hemp has been deducted by subtracting the concentration found in the soil from the concentration found in the flow through.In order to optimize the design of an adsorption system to remove fungicide from solutions, it is important to establish the most appropriate contact time used in batch experiments. Fig. 1 shows the amount of difenoconazole adsorbed by a hemp-based material versus the contact time for concentration of difenoconazole of 12 mg/L . The amount of fungicide adsorbed increased with contact time until reaching a constant value where no more fungicide was removed from the solution. These kinetic results indicated that adsorption process was uniform with time and can be considered very fast because of the largest amount of difenoconazole adsorbed to the material within the first 60 min. The process could be divided in three regimes: the removal is increased instantly at initial stages, from 5 to 60 min, e.g. after only 5 min, 33.3% of fungicide was removed; then the removal keeps increasing gradually from 60 to 120 min, until the equilibrium is reached and remains constant.

For a contact time of 240 min, the removal was 93.5%, indicating strong interactions between difenoconazole and binding sites present in the main fiber constituents, i. e cellulose, hemicellulose and lignin. The remaining concentration of difenoconazole become asymptotic to the time axis after 90 min of shaking and the amount of difenoconazole showed no significant difference when the contact times were longer than this. Similar results were obtained with a concentration of 1.2 mg/L.Industrial hemp is a multipurpose crop, whose fibre has a wide range of industrial applications . The stem of C. sativa is used to extract natural fibres. The stem contains two types of fibres, known as bast and hurd , which differ in their biological, chemical, and physical properties . Bast fibres are crystalline cellulosic fibre bundles located in the phloem at the periphery of the C. sativa stem . They consist of primary bast fibres, which are generated from the procambium, and secondary bast fibres, which are generated from the vascular cambium . The woody core, which contains xylem vessels, makes up the inner hurd fibres and is rich with lignin . During development, C. sativa stems exhibit basipetal gradient of lignification. Compared to the younger parts, the older parts of the stems show both the primary and secondary bast fibers, and the xylem are more developed . Retting is a process used to extract bast fibres in the phloem tissues through dissolving certain cells and constituents surrounding the fibre bundles, such as hemicellulose, lignin, and pectin . The main retting methods are chemical, mechanical, enzymatic, field retting , and microbial approaches, and they influence the quality and quantity of the fibres . Other factors that also reportedly contribute to fibre quality and quantity are morpho-anatomical traits and the cellular biochemical composition of C. sativa stems . Changes in the C. sativa stem from vegetative to flowering stage affect fibre quality and quantity owing to significant chemical and structural changes . However, other variables, such as genotype, environment, management, and their interaction, also affect raw C. sativa fibre quality and yield . Quantity and quality parameters of C. sativa have been extensively studied. For instance, fibre yield was known to be largely influenced by agronomic practices, environment, and genotype . Similarly, biochemical quality of fibre bundles, their lengths, and stem processability vary between C. sativa genotypes .

Physical properties and mechanical behavior of C. sativa fibres such as tensile strength , compression , elastic modulus , thermal properties , grow tent hydroponic moisture retention , colour , crystallinity , surface properties , and bundle architecture have been widely evaluated. However, there are limited studies that examine the effect of the genotype on physico-mechanical properties. Therefore, further research on this area will identify suitable genotypes that form different end products. The C. sativa genotype has been shown to be an important factor in determining several quantity and quality parameters of fibres . However, C. sativa germplasm is complex. Genetic reticulation from prolonged domestication and haphazard breeding have made it hard to identify genotypes . Generally, the genotypes are classified according to a wide range of attributes: i) population types–for instance, wild, landraces, and cultivars; ii) gender as they are dioicous or monoecious; iii) stem colours as yellow and green; iv) flowering time, which include early, intermediate, and late flowering genotypes; v) application–fibre, seed, dual , phytochemical , and ornamentals . Dioecious C. sativa genotypes have shown higher fibre yields than monoecious C. sativa . Mechanical properties and the morphology of the fibres of C. sativa are also reportedly affected by gender . Another study has shown that the C. sativa genotypes with yellow stems exhibit greater mechanical processability than green-stemmed genotypes and contain more bast fibre yield . Further, late-flowering genotypes have shown a high fibre yield compared with early flowering genotypes . While dual-purpose or multipurpose genotypes have been produced in hemp-breeding programs , there is no clear split between fibre, seed, and phytochemical type male plants , and their potential for fibre production has not been investigated. Therefore, more studies are needed to unveil the effect of genotypes on fibre production, linking stem anatomy and morphology with fibre properties. Moreover, the identification of C. sativa genotypes belonging to non-fibre categories, which potentially produce quality fibres, is important for the fibre industry. The objectives of the present study were to; 1) identify the morphoanatomical differences of the stems of C. sativa genotypes, 2) compare the physico-mechanical fibre properties of different C. sativa genotypes, 3) understand the effect of the stem colour of genotypes on biological and/or mechanical properties of hemp fibres, and 4) test the fibre quality of non-fibre type C. sativa genotypes. To achieve the objectives, we evaluated the physical properties of hurd and bast fibres from various C. sativa genotypes extracted using chemical, microbial, and enzymatic retting methods and tested the stem morpho-anatomical differences between the C. sativa genotypes.To score the morphological characters of stems, accessions were randomly chosen. A total of 10 fibre-relevant discrete and continuous characters were scored for each genotype. Morphological characters, character-state definitions, and methods of scoring are presented in Mendeley Data: Table S1. Heights of live plants were measured using a measuring tape and the number of grooves on the stem, branch number, and leaf number were counted after uprooting at the full flowering stage . Stem cross-sections were measured using a digital reticule of the Olympus DP73 stereo microscope at 63 on fresh stem sections. The stem curvature and inflorescence position of the herbarium specimens and colours of the freshly peeled stems were visually inspected. The internodal lengths of the digitised herbarium specimens were measured using ImageJ version 2 . Only continuous variables were used for statistical analyses.

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It will then be possible to define production compaction regarding target values of multi-physical properties

Posted on August 12, 2022 by hemp2022

The relatively lower intensity of this 915 cm−1 band suggests that the epoxy resin was almost fully cured. All these epoxy bands predominate in the composites in Fig. 5. Additionally, few bands characteristic of the hemp fiber, Fig. 5, such as 2916, 1510, 1160 and 1030 cm−1 still appear in the composites spectra in Fig. 5, although with less intensity. This might be interpreted as an indication of active interaction between the epoxy and the hemp molecular groups. Similar results were also found for hemp fiber/polyester composites but corresponding discussion is beyond the scope of the present work. It is only worth mentioning that FTIR results for epoxy and polyester composites disclosed evidence of hemp fiber molecular interaction with both thermoset matrices, which contributes to its ongoing mechanical reinforcement. Table 1 presents the results of 3 points bending tests, in terms of flexural strength and modulus, for both epoxy and polyester composites reinforced with different volume fractions of continuous and aligned hemp fibers. In this table it is also presented flexural results for plain epoxy and polyester, as control specimens. The results in Table 1 are plotted in Figs. 6 and 7 for visual interpretation. In these figures it is worth noting that epoxy composites with 30 vol% of hemp fibers display a marked increase in both flexural strength and modulus. This characterizes an effective reinforcement. On the other hand,incorporation of hemp fibers into polyester composites does not improve the mechanical properties of the matrix. The statistical validation of these flexural results were analysed by ANOVA and Tukey test. Table 2 presents the values of P for ANOVA with just one factor. In this Table 5 % is the level of significance to determine if in fact exist differences between a given set of results. If P is greater than 0.05, No difference should exist in the behavior for any volume fraction of hemp fiber in the set of values. On the contrary, if P is smaller than 0.05 then, statistically, Yes, a difference must be considered.

The ANOVA analysis in Table confirmed that hemp fiber incorporation into epoxy composites causes a significant difference. In this case,trim bin tray as aforementioned, a marked reinforcement for 30 vol% of fibers shown in Figs. 6 and 7. An apparent contradictory assertion might exist for the possibility of significant difference, Yes, in the flexural modulus of polyester composites in Table 2. However, a close look in the corresponding results in Fig. 7 reveals a significant increase for 10 vol% of hemp fiber. The possible reinforcement at this volume fraction should be further investigated. The individual comparison between pairs of distinct volume fractions of hemp fibers in the flexural properties of epoxy and polyester composites was performed by the Tukey test and presented in Tables 3 and 4. In these tables the sign means that the values are statistically different while means statistically equal, with 95 % level of confidence. The results of the Tukey test in Tables 3 and 4 disclose some points worth mentioning. First, for both the flexural strength, Table 3, and modulus, Table 4,the values for 30 vol% hemp fiberin epoxy composites are marked different as compared to any other volume fraction . In association with the results in Table 1 and Figs. 6 and 7, this indicates a comparatively stronger reinforcement caused to the epoxy matrix by incorporation of 30 vol% of hemp fiber. Second, incorporation of hemp fiber into polyester matrix would not cause a sensible difference, except perhaps for a possible relatively small improvement in the flexural modulus for 10 vol% addition. For practical purposes this flexural modulus must be further confirmed. Table 5 presents the results of tensile strength and elastic modulus for both epoxy and polyester composites reinforced with different volume fractions of continuous and aligned hemp fibers. In this table it is also presented corresponding tensile results for plain epoxy and polyester, as control specimens. The results in Table 5 are plotted in Figs. 8 and 9 for visual interpretation. In both figures the tensile strength and elastic modulus of the epoxy composites are higher than those for polyester composites. Moreover, within the limits of precision , the 30 vol% hemp fiber/epoxy composites display values of strength and modulus superior to the plain epoxy. This is an indication of de facto mechanical reinforcement associated with this volume fraction of hemp fiber. By contrast, in composites with polyester matrices, the hemp fiber incorporation is not providing efficient reinforcement.

The large dispersion related to the standard deviation in Figs. 8 and 9, could be a reason. Indeed, the average values for 30 vol% hemp fiber/polyester composites are higher than corresponding ones for plain polyester. This must be further investigated. However, the following statistical analysis might contribute to clear this question. The data obtained in tensile tests and used to evaluate the results in Table 5, were subjected to the analysis of variance and Tukey test, similar to the flexural test data. Table 6 presents the ANOVA values of “P”. In this table, considering that 5 % is the level of significance,there ought to be a significant difference between results if P < 0.05. Reversely, if P > 0.05 then no difference might be attributed to the mechanical behavior of the distinct volume fractions of hemp fibers incorporated into the composite matrix. As shown in Table 6, based on the ANOVA hypothesis, the incorporation of hemp fibers into epoxy composites causes a statistically significant difference in the tensile strength and elastic modulus. In other words,the hypothesis that the values are the same can be rejected with 95 % confidence. According to the results in Table 5 and Fig. 8, this difference is associated with a reinforcement effect. The same applies for the tensile strength of polyester composites. However, there is no significant effect on the elastic modulus of polyester composites with incorporation of up to 30 vol% of hemp fibers. The statistic interpretation between volume fractions of hemp fiber in the tensile properties of epoxy and polyester composites is given by the Tukey test results in Tables 7 and 8. As shown in Table 7, only the results of 30 vol% hemp fiber incorporation can be considered different in confront with any other volume fraction for the tensile strength of epoxy composites. It is also worth noticing that, as for the elastic modulus of epoxy composites in Table 8, not only the 30 vol% but also the other hemp fibers incorporation are different than plain epoxy . Considering the results in Table 5 and Figs. 8 and 9, one can affirm that the 30 vol% hemp fiber indeed reinforces the epoxy matrix. Moreover, these hemp fiber epoxy composites have tensile properties substan-tially higher than those of polyester composites, Figs. 8 and 9, in which the Tukey tests results, Tables 7 and 8, are not supporting a reinforcement effect.

A reason for the difficult of hemp fibers to reinforce the polyester matrix, as emphasized in both flexural and tensile results, might be a poor fiber/matrix interaction. Fig. 10 shows SEM images of tensile fracture of 30 vol% hemp fiber in polyester composites. In these images the poor adhesion between hemp fiber and polyester matrix is indicated by arrows. As a final remark, it is worth mentioning that the ANOVA and Tukey test statistical analysis for both flexural and tensile results prove, for the first time, that the incorporation of 30 vol% hemp fiber in epoxy composites provides an effective reinforcement. Moreover, no evidence of reinforcement was statistically found for similar incorporation in polyester composites. This may contribute to a practical decision regarding the amount of hemp fiber and type of thermoset matrix to be applied in ballistic armors.The density of composites is mostly implied by the compaction stress applied during their production, among other factors. The influence of compaction on physical properties of composites has been highlighted by Balciunas in the case of hemp-sapropel composites compacted at 20, 40 and 60% of their initial volume. This study focuses on the composites obtained with hemp shiv and black liquor. Hemp shiv are lightweight aggregates with high porosity and interesting hygrothermal properties. This makes them perfectly suited for the development of bio-based insulating materials. They are the most commonly used aggregates in the literature for the production of building materials. Black liquor is a renewable binder from local industry, is better for the environment than using petroleum-based binder . More, pollen trim tray the use of black liquor leads to a better hygrothermal properties of bio-based composites than the use of petroleum-based binder as highlighted in previous study. Black liquor is readily available component since ten tonnes of black liquor are produced per tonne of pulp using the Kraft pulping process. Currently, black liquor is mainly used for the production of energy. However, efficient energy production is cumbersome and expensive. It is therefore important to seek to enhance this co-product in a different way. Due to its chemical composition , black liquor represents an interesting alternative for the synthesis of sustainable chemicals. For this study, the composites are produced with the same hemp shiv to black liquor ratio but seven different compaction stresses applied during forming step . Thus, this study investigates the effect of compaction conditions on density, porosity, mechanical, thermal and hygric performances of composites.For each kind of composites, six specimens are produced. Three of them are used for thermal and hygric characterization, the three others for mechanical characterization and measurement of skeleton density.

The same black liquor to hemp shiv dry mass ratio of 15% is used. This value is chosen in order to ensure a good cohesion. For preparation, the hemp shiv are mixed with the black liquor in a mixer with a flat paddle during 5 minutes. The mix is split into three parts to produce three specimens. Specimens are molded and compacted 5 times using an Instron 5988 testing machine fifitted with a upper plunger, to ensure a good particles arrangement. They are maintained under compression and heated , cooled to room temperature and demolded .Polypropylene – natural fiber composites are of great commercial interest because they are lightweight, environmentally friendly, show high performance/cost index, high flexibility, low abrasiveness and low impact on human health. The high flexibility of natural fibers, which are bent during processing and not fractured as in the case of mineral fibers, is especially interesting for automotive applications. Despite the intense study of these composites, the industrial application of PP/NF composites is not as large as expected. This is partially determined by the weak interfacial adhesion, characteristic to the polymer composites with NF. Fiber treatment or coupling agents are generally used to overcome this drawback. Chemical treatments of NF including alkali, acetyl, acryl, isocyanate or silane modification are the most popular. In particular, silane treatment of hemp fibers , with or without an alkali pretreatment shows some benefits on the mechanical properties of polymer composites containing these treated fibers. Nevertheless, natural fiber – polymer composites show lower mechanical properties compared to glass fiber – polymer counterparts due to the inherently lower mechanical properties of NF compared to GF. In addition, the treatment of the fibers is often expensive and harsh to the environment. Other approaches such as a higher aspect ratio or a better dispersion of the fibers were tried to ensure better mechanical properties in PP/NF composites, higher fiber length and aspect ratio ensuring better properties. Although continuous fiber composites show better mechanical performance, the short fiber composites are easier to process and cheaper and they are required for the fabrication of injection molded parts. Some works have shown that long fibers increased the stiffness and short fibers the ductility of polymers and the incorporation of both long and short fibers of the same origin may lead to optimized mechanical properties by self-hybridization. However, agglomerations may be more frequent for very long fibers, leading to poor processing and lower mechanical properties . For an efficient stress transfer from the polymer to the fibers, fiber length should be longer than a critical value. Fu and Lauke showed that the composite strength increases rapidly with the mean length close to the Lc value and does not vary anymore for very long fibers .

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The increase in the conductivity is mainly due to the wide difference between that of the water and air

Posted on August 11, 2022 by hemp2022

Among the 4 harvested industrial hemp products, diesel fuel consumption and fertilizer were the inputs that were most affected in the field subsystem and together ranged from 73 and 82% of the total impacts, while machinery upstream manufacturing accounted for a minor proportion of the requirements . These results were also confirmed by Zampori et al. who found that fertilization is one of the main impacting processes in industrial hemp cultivation and harvest. Another energy and environmental aspect to emphasize is related to irrigation water. The cultivation of industrial hemp in Mediterranean climates, with low rainfall during the growing season, causes irrigation practices to be a fundamental requirement. This practice was included in this study, where the water sources at both experimental sites came from pressurized irrigation networks with negligible direct energy requirements. Moreover, as already stated, industrial hemp cultivation in southern Mediterranean conditions requires higher irrigation volumes, in contrast to northern environments, but has lower water requirements than other specialized crops, such as maize, that are commonly utilized in ADPs. The industrial hemp seed oils that were obtained from plants cultivated in contaminated soil can be used for nonfood products, such as oil, to revive fine furniture woods and in the biodiesel industry. In fact, biodiesel is one of the most commonly accepted complementary fuels for diesel engines, where in recent years, the cost and competition with the food sector have been decreased by using nonedible feedstock . Another application of nonedible oil has been proven by QuilesCarrillo et al., who discussed the use of maleinized industrial hemp seed oil to reduce the intrinsic brittleness of polylactide materials without compromising their mechanical resistance and to construct toughened biopolymer pieces, plant benches which can find interesting applications in, for instance, rigid packaging.

The AD subsystem allowed us to explore the energy and environmental benefits of using the industrial hemp biomass that was obtained from contaminated soil for biogas production while avoiding secondary pollution. The digestates were modeled to be dewatered by using the heat from the CHP unit and then incinerated in a BFPP for electricity production. This solution, because of the reduction in the biomass to be disposed of in authorized plants, enables us to reduce the disposal costs and to obtain energy from renewable sources. To the authors’ knowledge, the use of industrial hemp as feedstock for ADP has been well discussed in the scientific literature; in contrast, the use of HM-contaminated industrial hemp biomass as feedstock for ADPs is absent. A recent review indicated that industrial hemp biomass is a suitable crop for AD applications with high biogas production yields. Plants that are obtained in the phytostabilization of trace element-contaminated soil may affect biomass biodegradability, while HMs affect the physiological and biotechnological environments in AD. In fact, HMs interact with the microbial community and affect biogas production in AD processes, where trace HMs can promote biogas and methane production, while excessive HMs cause inhibition. Lee et al.demonstrated that the inhibition derived from HM-contaminated biomass was negligible, consequently, AD seems to be feasible for the disposal of HM-containing crop residues from phytoremediation sites. However, the release characteristics and fates of HMs should be carefully considered to predict the stability of the AD process for HM-containing biomass. Regarding BFPPs, greater energy and environmental benefits might be achieved by using the waste heat that is generated by these plants. As reported by BEN, most of the heat derived from cogeneration plants is used in the same facilities, while a minor proportion is used in district heating networks to provide heating services to the domestic sector. Instead of dispersing the waste heat that is generated by thermoelectric power plants into the atmosphere, these plants might convey this heat for useful consumption, which would thus avoid burning fossil fuels that would otherwise be necessary to be consumed to provide the same heating service.

The disposal of biomass ash represents a point of debate in environmental studies. The ash yields from biomass combustion range from 0.4 to 6%, and the ash compositions vary depending on the nature of the incinerated biomass. For this reason, it is important to individually characterize each type of biomass ash prior to finding an appropriate utilization approach. Biomass ash disposal has been found to be an influencing factor in the bioenergy and biowaste supply chain, while other studies have found that the contributions of the final disposal of biomass ash were not significant or were excluded from the study boundaries. Biomass ash is free of nitrogen and contains large amounts of micro- and macronutrients that are highly suitable for mineral soil amendments, the biological reclamation of degraded areas and dewatering sewage sludge. In addition, a recent review by Cui et al. emphasized that the incineration of contaminated biomass in modern incineration systems represents a technologically and economically feasible approach for treating hyperaccumulator plants, where ash residues could be pretreated and employed to produce construction materials and high-density glass-ceramics. Modern incineration systems could employ environmentally sound technologies that would perform better than pyrolysis and gasification-melting plants because of several benefits of flue gas cleaning, ash recycling, and the combined heat and power cycle. Moreover, these authors found that the efficient management of metals and bottom ash may decrease the volumes of waste landfills and reduce the consumption of raw materials. Finally, these results identify the great potential of using contaminated areas for bioenergy production while minimizing the exploitation of natural resources and avoiding pollutant emissions into the environment. As suggested by Pulighe et al. , the cultivation of marginal lands for bioenergy production provides ample opportunities to conduct successful feedstock production in unmanaged areas. Currently, HM contaminated soils are mostly unproductive and require expensive and long-term remediation programs to be turned into productive areas . Recently, the use of natural fibers has increased considerably due to its availability, low-density and price compared to synthetic fibers. Those factors are responsible for the apparition of a new polymer science and engineering research.

Natural fibers were introduced with the intention of yielding lighter composites, coupled with lower costs, compared to the fiber glass reinforced polymer composites. Natural fibers have a lower density than that of glass fiber , which ensures the production of lighter composites. Conventional petroleum based epoxy resin, polyurethane , are used extensively with natural fibers, such as hemp, jute, sisal, and kenaf.Recently, the rapidly expanding use of composite components in construction, sports, leisure, and other mass production industries, has been focused on sustainable and renewable reinforced composites. Building insulation is one of the most applications of this material, mechanical and thermal properties are the obvious needs in this area. Physical properties of polyurethane-based composites have been widely studied. Hadjadj et al. demonstrated that Young’s modulus of PU-Alfa fibers composite improved linearly with the embedded cellulose content, it increase by 250%–700% when the fiber reinforcement is raised from 5% to 30%. Radzi et al. have also studied the influence of the addition of Roselle fiber on the mechanical and thermal properties of polyurethane composites they concluded that the tensile and fluxal strength increase with fiber contents, 40 wt% fiber content showed the highest strength. Oushabi et al. studied the effect of polyurethane reinforced by date palm waste, they showed that this reinforcement affects the mechanical properties of the resulting composite, the thermal conductivity of prepared composite makes it possible to consider them as competitive for the development of effective, inexpensive insulating materials and safe. Silva et al. studied the influence of Eucalyptus grandis fibers on rigid PUs and found that the addition of 16% natural fiber drastically increased their mechanical strength and thermal conductivity. Hemp fiber is one of important natural fibers used in industrial areas, which has relatively short cropping cycle and can be easily grown in a large array of environments. In addition, hemp characterized by a tensile strength of up to 1110 MPa is one of the strongest fibers among all bast fibers. There are previous studies reporting on mechanical properties of PU-hemp fibers composites they concluded that treated hemp fibers with alkaline, silane or acetyl solutions can improve tensile and flexural properties of composites. Several works are interested in the mechanical behavior of polyurethane- natural fiber composites, but few have studied the effect of this reinforcement on the thermal conductivity. The aim of this paper is to study the properties of hemp fiber reinforced composites with differential fiber contents . Mechanical, hygroscopic and thermal conductivity, of HF/PU composites were examined.

During their life cycle service, rolling bench the composites materials are often exposed, for long periods, to humid environments. However, moisture generates heterogeneous internal stress fields in this type of material, which leads to the changes in thermal and mechanical properties. Thus, it is interesting to predict the absorption of water for all formulations in order to estimate their sustainability. Water uptake effects on thermal conductivity have been studied by they reported that the thermal conductivity of composite materials increases with volumetric water content. The origin of this increase is due to the saturation in water, in this state the water occupies the open pores of the materials.The water uptake can also affect the mechanical properties of composite materials; the water molecules change the structure and properties of the fibers, matrix and the interface between them, leading to the loss of compatibilization between the fibers and the matrix, to the chain reorientation and shrinkage of matrix also lead to the degradation of natural fibers by a hydrolysis mechanism. All these factors led to decrease mechanical properties of the composite. The water absorption amount was calculated by the weight difference between the samples exposed to water and the dried samples using the following Eq1. Water absorbed percentages in terms of a time for all samples are showed in Fig. 6. The same behavior was observed for all samples, composite materials absorbed water in two stages, and during the first stage the speed of absorption is very fast reaching a certain value, then slows and approaches saturation after prolonged time following a Fickian diffusion process. Both the initial rate of water absorption and the maximum water uptake increase for all hemp fiber composites samples as the fiber content increases. From sorption, diffusion and permeability coefficients values shown in Table 2 it is clear that the polyurethane absorbs less distilled water than prepared composites due to its closed cell structure which prevents water absorption and moisture storage. The incorporation of hemp fibers, highly hydrophilic, increase greatly the water content that can be retained by the composite materials, this behavior has been observed in other works of hemp fibers and polymer matrix composites. Water absorption increase at higher fiber content, the composite PU 30%, has the largest water uptake and permeability coefficient, which limits the use of these renewable resources to high percentages exceeding 25%.The performance of materials is always presented in terms of their mechanical characteristics, such as tensile properties, flexural properties, compression properties, impact properties and wear behavior. It is evident from Fig. 7 that all composites showed a ductile behavior, The properties of the polyurethanes vary considerably with the fiber content, reinforced composites with hemp fibers showed better tensile strength than the polymer matrix. The tensile strength of composites has been found to increase with hemp fibers reinforcement. Composites with 15% loading exhibit maximum tensile strength, followed by 10%, 5%, 20%, 25% and 30% loadings. The failure of reinforced composites under tensile load could be due to breaking of cellulosic fibers at the weaker point followed by further propagation under the applied load that is transferred to adjacent fibers by the matrix, leading to complete rupture of the composites. From the value of Young’s modulus and tensile strength reported in Table 3, it is clearly asserted that there is a gradual decrease in the strength when increasing the percentage of the hemp fibers up to 20%. The tensile strength observed is better at 15% hemp fiber. The flexural strength results of hemp fiber composites follow the same trends obtained in tensile strength tests. Table 4 shows that the flexural properties increase up to 15% of fiber, and then keep this increase, after 20% of fiber we observed also the deterioration of the mechanical properties.

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The addition of hemp to a pelleted diet did not seem to have a beneficial effect on the incidence of gastric ulcers

Posted on August 10, 2022 by hemp2022

All diets were ground to pass a 5 mm sieve.In the Hemp Cake diet,the amount of wheat and rapeseed meal was reduced to ensure the same energy and protein level as in the other diets,and hemp seed cake was added prior to pelleting at a commercial feed factory.The Pellets and Hemp Hulls diets were based on the same ingredients,thus to distinguish between the different feeds before preparation of the experimental diets,micro grits were added to the Meal diet and the Hemp Cake diet.After pelleting,hemp seed hulls were added to the Hemp Hulls diet at Grønhøj Research Station via the feed facility Spotmix.No segregation of the hemp seed hulls from the pellets was observed.It was assumed that hemp seed hulls,added to the Hemp Hulls diet,do not contribute with energy or nutrients.The diets were optimised according to the nutritional recommendations for growing-finishing pigs from 30 to 105 kg BW and contained the same amount of energy per kg feed in all groups.The hemp seed products were delivered by Nørding Oil.A wet sieve analysis was performed to determine particle size distribution using an electronic sieve shaker ,and the diets were analysed for major nutritional composition at Eurofins Steins Laboratory A/S.Saliva samples were collected from clinically healthy pigs on the day before slaughter by allowing the pigs to chew on a gauze until it was soaked.The sampling started in the morning and finished after noon.No gustatory stimulation was used before saliva sampling.The gauze units with saliva were put into falcon tubes and immediately placed on ice.After completing the sampling,the saliva samples were transported to the laboratory at Aarhus University,Foulum,Denmark and processed immediately.Saliva was extracted from the gauze units by centrifugation at 10 000g for 10 min at 4  C.The saliva samples were stored at  20  C until sample preparation and analysis.Immediately after slaughter,drying racks stomachs were collected and subsequently transported to Laboratory for Swine Diseases,Kjellerup,Denmark for examination.

At the laboratory,the stomach content was collected to assess the consistency of the stomach content based on the solid particle sedimentation percentage.The stomachs were washed and scored using an ulcer index scale for changes from 0 to 8 and a total index scale from 0 to 10,which includes chronic changes,i.e.,scar tissue and oesophageal strictures.The saliva samples for metabolomics analysis were selected based on the ulcer index scores since we were interested in examining possible biomarkers for acute gastric ulcers and not for chronic changes,as these changes are not expected to result in biomarker responses at this stage.The groups were established as follows: healthy pigs: ulcer index score 0; pigs with hyperkeratosis : ulcer index score in the range of 1–3; pigs with active ulcers: ulcer index score in the range of 6–8.In the present study,the four experimental diets were formulated to create the following expected differences: the meal and pelleted diets were selected based on previous research revealing differences in prevalence of gastric ulcers ,and were formulated to explore potential salivary biomarkers for gastric ulceration.The hemp diets were formulated to investigate the potentially anti-inflammatory effect of hemp and the swelling capacity ,which are two mechanisms considered important to prevent gastric ulcers.The higher prevalence of gastric ulcers observed in pigs provided pelleted feed compared to pigs provided meal feed is in accordance to what other studies have reported.However,the odds of having severe gastric ulcers tended to be lower in pigs fed Hemp Hulls compared to pigs fed Pellets,suggesting that hemp seed hulls might have a positive effect in the prevention of severe gastric ulcers.The solid phase percentage of the gastric content was higher in pigs fed Meal compared to pigs fed Pellets,which is in agreement with other studies.In addition,the solid phase percentage of the gastric content in pigs fed Hemp Hulls was higher compared to that of pigs fed Pellets,indicating that the addition of hemp seed hulls to a pelleted diet results in a more solid stomach content,presumably due to the swelling capacity of hemp seed hulls.The feed conversion ratio was poorer in pigs provided meal feed compared to pigs provided pelleted feed,which is in line with the literature.

The main reason for this is considered to be the lower nutrient digestibility of coarsely ground diets due to impaired accessibility of endogenous enzymes to the substrates in the feed particles.Another contributing factor can be the higher feed waste when feeding meal feed as compared to pelleted feed.The main objective of this study was to examine a possible correlation between salivary metabolites and ulcer index score and to identify metabolites,which could be used as potential biomarkers for gastric ulceration in pigs.The argument for combining the healthy group and HK group is that the pigs in the group with HK are assessed as being in the very early stage of ulceration.In the stage of HK,no loss of epithelia has occurred,and thus no ulcer development has taken place yet.Instead,the stratified squamous epithelium around oesophagus has gradually changed structure observed as thickening and roughening of the epithelium.Thus,in the stage of HK,we do not expect a strong inflammatory response or effect on salivary metabolites.Several lipid metabolites including different oxylipins were detected in saliva as discriminating metabolites between the healthy/HK group and the group with ulcers.Lipid mediators play a role in the initiation,amplification and resolution of the inflammatory response as well as in signalling events.Oxylipins are oxidation products of polyunsaturated fatty acids,which are formed via one or more mono- or dioxygen-dependent reactions.In addition,oxylipins are important regulators and markers of a wide range of normal and pathological processes in the body.Eicosapentaenoic acid and arachidonic acid are two of the most important long-chain polyunsaturated fatty acids in terms of precursors to oxylipins with strong anti- and proinflammatory properties,respectively.The biosynthetic origin of oxylipins is still largely unknown; however,it is well established that oxylipins are found in all body tissues,urine,blood and saliva.The majority of the salivary oxylipins were tentatively identified to belong to the oxylipin group TriHOME,DHOME or DiHODE,and are all derivatives of linoleic acid.The linoleic acid metabolism,including the pathways of the identified salivary oxylipins that derive from linoleic acid,is shown in Fig.3 developed by KEGG.

Linoleic acid is an essential n-6 fatty acid and is a precursor of arachidonic acid.Arachidonic acid can via the cyclooxygenase pathway be converted into eicosanoids including prostaglandins.Prostaglandins,such as prostaglandin E2,are known to play a role in the induction of acute inflammation as well as in the protection and healing of gastric ulcers.Production of prostaglandins is generally low in uninflamed tissue but increases rapidly in acute inflammation before the recruitment of immune cells.In this study,a prostaglandin metabolite,13,14-dihydro-15-keto-tetranor prostaglandin F1a,was tentatively identified and found to be increased in saliva of pigs with gastric ulcers; however,the increase was not significant.The presence of a prostaglandin metabolite reflects the biosynthesis of prostaglandins via the cyclooxygenase pathway.Linoleic acid shares a common metabolic pathway with alpha-linolenic acid.Thus,linoleic acid competes with alphalinolenic acid in binding to the enzyme D6-desaturase to direct the metabolism towards more pro-inflammatory n-6 polyunsaturated fatty acid-derived compounds such as arachidonic acid and less anti-inflammatory eicosapentaenoic acid.In addition,arachidonic acid competes with eicosapentaenoic acid as substrates for lipoxygenase and cyclooxygenase to produce immunoregulatory eicosanoids,including prostaglandins.In contrast to arachidonic acid-derived eicosanoids which are mainly pro-inflammatory,eicosapentaenoic acid-derived eicosanoids have anti-inflammatory effects to rebuild immune homeostasis such as by reducing the expression of interleukins.Pigs with acute gastric ulcers might have greater synthesis of pro-inflammatory prostaglandins than healthy pigs to induce an inflammatory response,restore tissue structure and physiological function,and eventually heal the ulcer.Acute inflammation may favour the conversion of linoleic acid to arachidonic acid and eventually the generation of pro-inflammatory prostaglandins,and thereby the conversion of alpha-linolenic acid to eicosapentaenoic acid via enzyme D6- desaturase will be reduced.Instead,alpha-linolenic acid might be converted to other metabolites including oxylipins such as 2R-HpOTrE.This could explain the significantly higher concentration of the alpha-linolenic acid-derived oxylipin,2R-HpOTrE,observed in pigs with acute gastric ulcers compared to healthy pigs.In addition,an upregulation of the pathway of linoleic acid into arachidonic acid could explain the lower concentrations of linoleic acid-derived oxylipins,including 9,12,13-TriHOME,9,10-DHOME/12,13-DHOME and 9,10-DiHODE/15,16-DiHOD E/12,13-DiHODE,observed in pigs with gastric ulcers compared to healthy pigs.Furthermore,the requirement for production of pro-inflammatory prostaglandins is probably lower in healthy pigs than in pigs with acute gastric ulcers.Thus,linoleic acid might mainly be converted into oxylipins in healthy pigs.

In addition,linoleic acid-derived oxylipins might have antiinflammatory effects and may be beneficial in terms of gastric health.The pelleting process might affect the lipid composition in the diet due to the potential oxidation of fatty acids.Unfortunately,fatty acid composition was not analysed in the experimental diets,cannabis drying and thus it was not possible to demonstrate that the significant lower level of linoleic acid-derived oxylipins observed in pigs with acute gastric ulcers provided pelleted feed was not caused by any differences in fatty acid concentrations in the diets.Metabolite identification revealed metabolites deriving from the feed.Since the pigs were fed ad libitum,and collection of saliva samples was performed without cleaning the mouth of the pigs,the saliva samples were most likely contaminated with feed residues.The possible contaminants from feed residues were considered during the metabolomics analysis,and multiple cleaning steps were performed to extract these residues.Contamination with feed residues cannot be fully avoided; however,to minimise feed residues in saliva samples,deprivation of feed several hours before sampling could be an opportunity to minimise feed residuals in saliva samples as well as performing a cleaning procedure of the mouth prior to sampling.Deprivation of feed prior to saliva sampling,however,was not possible in this study,as it might affect the health status of the stomach.The metabolomics analysisrevealed the presence of a disaccharide,which might be sucrose,lactose or isomaltose,in the saliva of pigs,which probably derives from the feed as well as azelaic acid,which is a dicarboxylic acid found in cereals,such as wheat,barley and rye.Daidzein,a metabolite from soybean meal,was identified as a metabolite,which contributed to the separation of the groups,found at significantly higher levels in healthy/HK pigs compared to pigs with ulcers.However,since the majority of the pigs fed the Meal diet were assessed as healthy,the increased level of daidzein in healthy/HK pigs might be explained by the significantly greater feed intake observed in pigs provided meal feed compared to pigs provided pelleted feed.In addition,the structure of the Meal diet might leave more residues in the mouth.Furthermore,a partial least-squares discriminant analysis model for healthy pigs fed the Meal diet vs pigs with ulcers fed the Pellets diet was built and showed a good separation between groups.However,since diet and health status were confounded,the model was excluded.Another metabolite,which probably derived from the feed,floionolic acid,found at a significantly higher concentration in healthy/HK pigs compared to pigs with gastric ulcers,is a longchain fatty acid found in vegetable fats and oils.This difference might also be explained by the greater feed intake in pigs provided meal feed compared to pigs provided pelleted feed.A sulphated compound was found to be significantly increased in healthy/HK pigs compared to pigs with gastric ulcers.Sulphated compounds found in saliva are probably a result of the metabolism.Since salivary glands with high permeability are surrounded by capillaries,saliva contains a variety of locally synthesised compounds as well as systemic compounds.Thus,it could be speculated that sulphated compounds produced elsewhere in the body,including the liver and kidney,possibly enter the blood circulation and eventually end up in the salivary glands where they are secreted in saliva.However,the role of sulphated compounds in gastric ulceration remains to be determined.In the current study,the pigs used for saliva sampling were not clinically diseased and therefore we did not expect them to suffer from inflammation due to other diseases.Thus,we assume that the identified salivary oxylipins were a result of an inflammatory response caused by gastric ulcers.However,the possible role of oxylipins in inflammation associated to gastric ulceration needs further examination.The development of industrial methods for production of bio-based products has been gaining attention in recent years.For the production of such products,industrial hemp can be considered as one of the efficient and sustainable renewable resources in the world that has proven itself for several hundred years.Industrial hemp can be grown as a fiber,seed,or dual-purpose crop.Traditionally,it is grown for its long and strong fibers.From the fibers production process,large amount of short woody fibers ,called shives or hurds,are formed.These shives are considered as solid waste.Therefore,shives are mainly used as a high-performance bedding material for animals.

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The addition of hemp fibres significantly increases the energy absorption capacity of the plain mortar

Posted on August 9, 2022 by hemp2022

The alkali treatment increased slightly the density of the reinforced mortar.No significant difference could be noticed between the bulk densities of all mortar groups after wet/dry cycles compared to those of their non-aged counterparts.The difference of NaOH concentration by the fibres treatment does not significantly influence the physical properties of the fibre reinforced fly ash-based alkali-activated mortars.The reason for that is that even the lowest NaOH concentration was enough to separate the fibres from a fibre bundle.The increased NaOH concentration does not lead to more efficient fibres separation.This leads to no difference by the composites mixing and leads to similar composites structure formation.After the addition of the fibres,the compressive strength of the mortar decreases.It can be seen that at the age of 28 days,46% higher compressive strength is achieved in the plain mortar than in the non-treated fibre reinforced one.The addition of fibres leads to increased porosity and decreased density ,which consequently leads to a lower strength of the mortar.However,since the alkali treatment of fibres refines the fibre mortar’s pore structure,lowers the total pore volume and slightly increases the density of fibrereinforced mortars ,it consequently results in increasing their compressive strength.Additionally,the alkali treatment eliminates the fibrous filaments on the surface of hemp fibres as well as cleans the surface and separates the fibre bundles into fibrils ,which results in a better fibre dispersion within the matrix.Thisprovides better homogeneity of the composite,which in turn results in enhanced compressive strength.The concentration of the sodium itself in the fibres treatment proved to have no significant influence on the compressive strength of mortars.A similar trend but less pronounced was reported in fibre reinforced cementitious mortars after the fibres were treated with sodium hydroxide solutions.Jo et al.showed that 5 mm-long jute fibre treated with 0.5% sodium hydroxide increased the compressive strength of the fibre reinforced cement-based mortar by ca.5%.Yan et al.used 50 mm-long coir fibre to reinforce the cement-based specimens.After the fibre treatment with 5% sodium hydroxide solution,the compressive strength increased by only 0.8%.After the wet/dry cycles,cannabis grow racks the plain mortar shows 75% higher compressive strength than non-treated fibre reinforced mortar.

The drop of the strength after the fibres’ addition is related to the higher porosity of the fibre reinforced mortar.In addition to this,the hemp fibres are hydrophilic,so during the wet/dry cycles,they absorb water and swell.This can introduce micro-cracks in the matrix and lead to fibre–matrix debonding,thus preventing an optimal stress transfer within the matrix.However,the alkali-treated fibres significantly reduce the strength loss.It is shown that up to 50% higher compressive strength of the fibre reinforced mortar could be achieved after the wet/dry cycles when fibres are previously treated with 6% sodium hydroxide.Even more important is that 6% sodium hydroxide-treated fibre reinforced mortars experienced no loss of compressive strength after the wet/dry cycles.Without the fibre treatment,fibrereinforced mortars lose 20% of their strength when compared the result after wet/dry cycles to the non-aged mortar’ result.TG-DTA plots of the mortar samples are illustrated in Figs.13 and 14.The bound water in the gel-like binder phase and the heat of reaction required for its decomposition are reported in Table 5.A higher heat of reaction in the plain mortar compared to the fibre reinforced mortar groups indicates a larger amount and a better-incorporated binder phase in the formed alkali-activated matrix,characterized by a binding potential.Mortars show a broad endothermic peak in the temperature range of 100 ◦C to 300 ◦C,especially those without hemp fibres.The observed weight losses can be related to the bound water loss.It is shown that there is more bound water in the plain mortar than in the fibre reinforced mortars.This could be an indicator of the pore sizes of the binder gel since the bound water is tightly held only in very small pores.The more bound water,the more small-size pores appear.This correlates to the porosity obtained by the MIP.The plain mortar results in a more pronounced amount of the smallest pores than fibre reinforced mortars.However,the alkali-treated fibre reinforced mortars result in slightly enhanced bounded water content in their gel-like matrices and the more optimal pore sizes distribution than the nontreated fibre reinforced mortar.This consequently leads to their higher compressive strength.The flexural strength of the mortars follows the same trend as their compressive strength.The addition of fibres decreases the flexural strength of mortars.The flexural strength of the plain mortar is 34% higher than the one of non-treated fibre-reinforced mortar,tested at the age of 28 days.This is the result of increased porosity and decreased density after fibres addition,which consequently leads to a lower strength of the mortar.Even though the flexural strength is mostly influenced by the matrix itself,it is noticed that with the fibre treatment,the flexural strength of the fibre reinforced mortar increases.The difference in the concentrations of the applied sodium hydroxide influenced only slightly the flexural strengths of the mortars.A similar trend but less pronounced was reported in fibre reinforced cementitious mortars after the fibres were treated with sodium hydroxide solutions.Jo et al.showed that 5 mm-long jute fibre when treated with 0.5% sodium hydroxide,increased the flexural strengths of fibre reinforced cementbased mortars by 3.6%.Yan et al.used 50 mm-long coir fibre to reinforce the cementbased specimens.After fibre treatment with 5% sodium hydroxide solution,the flexural strength increased by 6.5%.After the wet/dry cycles,the plain mortar shows 46% higher flexural strength than the non-treated fibre reinforced mortar.This results from the hydrophilic nature of hemp fibres and their ability to absorb water and swell during wet/dry cycles.This could cause microcracks in the matrix and lead to fibre–matrix debonding,which decreases the flexural strength of a mortar.

The alkali-treated fibres could reduce the strength loss,by reducing the water absorption capacity of the fibres themselves.On average 23% higher flexural strengths are achieved after the wet/dry cycles.The flexural strength of all mortars after wet/dry cycles was on average 33% lower in comparison to their non-aged counterparts.In the fibre reinforced mortar groups,this difference is even lower in the case of 6%- and 9% sodium hydroxide-treated fibre reinforced mortar.These mortar groups show almost the same flexural strength drop as plain mortars.The most important contribution of fibre reinforcement in the mortar matrix is in the prolongation of crack initiation in the pre-cracked state and in the slowdown of crack propagation in the cracked state which results in enhanced energy absorption capacity under flexure.The presence of fibres in the matrix changes the mortars’ behaviour from quasi-brittle toward a more ductile one dependent on the type,geometry and dosage of the fibres.Plain mortars have almost no deformation capacity after the maximal flexural force is reached,indicating a negligible energy absorption capacity in the post-peak region.On the other hand,hemp fibre reinforced mortars have a significantly higher deformation capacity in the post-peak region,indicating a much higher energy absorption capacity than plain mortar.With the fibres treatment the energy absorption capacity can be increased even more.The fibre-bundles separation leads to better fibre dispersion through the matrix.In addition to this,the fibres treatment increases the roughness of the fibre surface resulting in a stronger fibre–matrix bond,which could be seen by the higher number of matrix particles attached to the treated fibres after 3PBT.The alkali pretreatment of hemp fibres leads to their surface fraying effect due to the degradation of the hemp components – hemicellulose and lignin.This chemical process could cause an improvement in interaction at the interface of the binding alkali-activated matrix and hemp fibers.At the age of 28 days,3% sodium hydroxide-treated fibre reinforced mortar has a higher energy absorption capacity than the nontreated fibre reinforced mortar.The further increase of the sodium hydroxide concentration in the fibres’ treatment slightly decreases a mortar’s energy absorption capacity ,keeping it still higher than the one of the non-treated fibre reinforced mortar.The enhancement of the energy absorption capacity with alkali treatment of fibres was also reported in cementitious materials.Jo et al. showed that the energy absorption of the jute fibre reinforced cement-based mortar increased by 6.5% when the fibres were treated with 0.5% sodium hydroxide solution,whereas Yan et al.reported an increase by 8.7% of the coir fibre reinforced cement-based mortar’s energy absorption when the fibres were previously treated with 5% sodium hydroxide solution.

When specimens undergo wet/dry cycles,the results show that nontreated fibre reinforced mortar has 343% higher energy absorption capacity than plain mortar.In the case of alkali-treated fibres,the energy absorption capacity of the non-treated fibre reinforced mortar increases even more,i.e.by 8%,19% and 15% for 3%-,6%- and 9% sodium hydroxide-treated fibre reinforced mortars,respectively.It seems that the higher concentration of the sodium hydroxide results in less hemicellulose in the fibres which leads to lower water absorption.This prevents the swelling of fibres,which causes micro-cracks in the matrix around the fibres and leads to fibre–matrix debonding.When comparing the results of the specimens after wet/dry cycles to those tested at the age of 28 days,it is seen that the addition of nontreated fibres to the matrix can significantly reduce the decrease of the energy absorption capacity of the plain mortar.With the alkali-treated fibres,cannabis grow system the decrease could be reduced even more.The energy absorption capacity of the mortar shows the lowest decrease after the wet/dry cycles when the fibres are treated with 9% sodium hydroxide.The fibres in that case reduce their water absorption capacity mostly.Besides,it could be seen that 3% sodium hydroxide treated fibre reinforced mortar before the wet/dry cycles has a higher percentage share of the energy absorption capacity in the later post-peak part of the force–displacement curve than after the wet/dry cycles.On the other hand,9% sodium hydroxide treated fibre reinforced mortar contributes more to the percentage share of energy absorption capacity in the post-peak part after the wet/dry cycles than it does before the aging.The reason could be that after the heat during the drying cycles,mortars continue with the further development of their system and increase the formation of mineral products while decreasing the amount of entrained pores.Including the higher fibres roughness after 3% sodium hydroxide treatment,this could lead to strong fibre–matrix bonds.The strong fibre–matrix bond leads consequently to a more pronounced fibres break after the failure of the matrix,which does not increase the post-peak part of the force–displacement curves.Therefore,in terms of the energy absorption capacity of the mortars when exposed to wet/dry cycles,9% sodium hydroxide concentration is considered as the most optimal fibre treatment.Hemp is an industrial crop that is commonly used in the textile,pharmaceutical,and paper industries.Hemp seeds are a by-product of hemp processing and contain 25–30% oil,20–30% protein and other nutritional substances.

Hemp seed oil contains more than 80% unsaturated fatty acids and a high content of functional components,including linoleic acid ,linolenic acid and other essential fatty acids,as well as tocopherols,vitamin A,minerals,etc.,which have a positive impact on cardiovascular,mental and immune diseases and can be added to foods as functional fats.HSO contains low levels of the psychoactive compound tetrahydrocannabinol  in compliance with European Union and American standards.THC is a polyphenol with high antioxidant properties,which enhances the antioxidant properties of the product.Therefore,encapsulating HSO in emulsions can improve its bioavailability,avoid oxidation reactions,and broaden its application scope.Mikulcov´ a et al.prepared HSO oil-in-water emulsion with emulsifier Tween to improve its stability and antimicrobial activity.Jarzebski et al.used pea protein as a stabilizer for HSO emulsions and the emulsions showed good results in terms of particle size and encapsulation efficiency.Proteins with amphiphilic properties can be used as emulsifiers,and similarly,hemp seed proteins can be used to stabilize HSO emulsions.Compared to common high-quality proteins ,HPI is hypoallergenic,highly digestibility,has a good composition of essential amino acids.This means a more nutritionally superior amino acid pattern.In addition,its solubility is low,and its emulsification ability can be affected by external factors such as pH during treatment.HPI-stabilized sunflower oil emulsions were prepared by Dapˇcevi´cHadnađevd et al.It was found that the interaction between HPIs affected the transient flocculation network and contributed to the emulsion stabilization,and the emulsification activity of HPIs was similar to the protein solubility curve.Tang et al.have compared the functional properties of different proteins,where HPI has lower emulsifying activity and emulsifying stability than soybean protein,rice protein and pea protein.Therefore,external more energy efficient means or devices are needed to assist in the preparation of stable emulsions,such as ultrasonic,microwave,microjet,etc.High-intensity ultrasonic is an emerging processing method with frequencies typically in the range of 20–100 kHz and intensities in the range of 10–1000 W/cm2.

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The actual values used in the industrial flax facilities are confidential and cannot be given here

Posted on August 8, 2022 by hemp2022

A first set of trials are performed at the industrial scale first,using flax dedicated machines and their associated settings to establish a reference.Then,a laboratory scale scutching and hackling equipment was used to investigate/optimise the scutching and hackling process parameters to improve the quantities of fibres and maximise their performances.Projections of long fibre yields in conjunction to dew-retted dry hemp stem yields are also given and permit to discuss the future of a complementary value chain in flax territories.A lab scale scutching/hackling extraction device was used.It,was used to separate the different plant fractions contained in the hemp stems with the main objective to obtain the long line fibres analysed in this study.The hemp stems are stabilised before testing at 65 % relative humidity and 23 ◦C.This lab-scale scutching/hackling device is composed of three distinct modules.The first one has the function of breaking the wooden part of the stems and allowing a first extraction of the shives and the dust.It is composed of a set of three pairs of corrugated rollers with adjustable distance between centres and speed of rotation.The material obtained is then automatically transported to a scutching system.It consists of two rotating turbines,which rotate in opposite direction to each other.Their role is to beat the fibres and to remove the shives still tied to the fibres.The residence time in the scutching module and the turbine speed are adjustable.Finally,the fibres are subjected to a progressive hackling stage to align the fibres and reduce technical fibre diameter.The hackles or combs are mounted on two rotating belts that can be adjusted in speed.The translation speed of the fibre is also adjustable.Stems from the retted and un-retted batches are subjected to extraction by scutching and hackling using the lab scale device.An additional part of the fibres from the dew retted stems were extracted using an industrial scale Depoortere scutching device and a Linimpianti hackling machine located at the “Terre de Lin” company.

Fig.1 shows the different steps of the industrial scutching and hackling of hemp stems.This scutching machine is composed of two distinct devices: a breaking system composed of a succession of horizontal fluted rollers and a beating stage which consists of successive pairs of rotating turbines,grow cannabis with each turbine rotating in opposite direction.The scutching machines are designed to process more than one ton of flax straw per h and globally deliver 250 kg of long line fibres.The hackling machine is a Linimpianti type equipment that was designed to process about 80 kg/h of scutched fibres.It is a fast and high production rate if one compares to traditional Mackie type machines which process globally up to 40 kg/h.For hemp,different settings were specifically applied to the scutching breaking and beating steps,but still with a high extraction speed,close to the one used for flax straw.The extraction parameters chosen for our device were optimised so that to obtain large quantities in mass of hackled long line fibres.Gentle extraction conditions have been applied by the lab-scale device with a low transfer speed during breaking and a low turbine rotation speed during scutching.Globally,a reduction of the transfer speed by 300 % and the turbine rotation speed by 400 % is applied in comparison to what is classically used in industrial scutching facilities for flax.As a result,some of the shives remain after the scutching stage,on the contrary to what is observed during industrial scutching.The type of combs and the hackling machine design offers the possibility to remove this wood without difficulty and to obtain clean long line fibres at the end of extraction.Following the stage of hackling and the realisation of a continuous sliver at the end of this process,the large count sliver is submitted to six drawing stages where the linear mass of the sliver decreases in our case up to a linear mass of about 150 tex depending on the settings.The used apparatus is a lab scale drawing system.This device mimics,at a reduced scale,the six drawing/doubling stages used in the flax spinning industry to prepare the slivers into rovings that will be used at the spinning stage.During the different stages of this process,six parallel flax dedicated systems using pin drive devices to bring the slivers and a wooden wheel to perform the drawing were used.This type of drawing system is also called “gill drawing system”.perform the different drawing operations.

During this stage,the sliver mass is reduced but it is also homogenised as between each drawing stage,six drawn slivers are each time grouped together before the following drawing.During these operations,the technical fibre diameter is also reduced when the technical fibres are pulled from the Gill system pins.The fibre diameter obtained at the end of the extraction and preparation processes was therefore investigated and compared for different batches at this stage.After processing the hemp stems through the various modules of the lab scale scutching hackling extraction device,several plant fractions are obtained.The shives,which are the woody part of the stems,can be separated from the dust generated during the extraction process and from the long line fibres and shorter fibres,also called tows.Thus,the by-products obtained at the output of each module are manually separated and weighed in order to determine the impact of the different extraction steps on each of the plant fractions as well as the yields.The study of the impact of the modules on the losses of the plant fractions is important in order to know which elements should be improved to increase the quantity and quality of the fibres.Fibre yield is computed at the end of the industrial scutching and hackling equipment.In order to investigate the impact of the different extraction steps on the mechanical and physical properties of the long line fibre,single elementary fibres are extracted after each module.Fibres are tested in tension and the evolution of fibre surface defect is investigated.The results obtained are compared to the initial potential of the material prior to any mechanical extraction.In the study of the industrial extraction of hemp fibres,fibres could only be collected after the scutching and hackling modules.To determine the initial mechanical potential of the elementary hemp fibres,prior to any mechanical extraction,fibres are manually extracted.To reach this objective,sections of stems are randomly taken and the bast peeled by hand.The elementary fibres are then carefully separated from the bast after soaking them in distilled water for about 10 s as specified in the NF 25-501-2 standard.Fibre samples were also taken after each extraction module of the lab scale scutching/hackling device.Thirty elementary fibres were then extracted from each batch to determine the impact of the various stages of the process on the mechanical properties of the fibres.The number of defects,as well as the morphological and mechanical properties of the fibres were evaluated.The main defects that can be observed on the surface of the fibres are kink bands which can be examined under polarized light as shown,for example,by Baley or Thygesen.

Kink bands are among the defects that can be visible on the surface of the fibres and are expected to be zones of weakness for the fibres as cracks were shown to preferably initiate from these zones.They can come from a disorientation of the cellulose fibrils due to some compression or bending loads.The number of kink bands on the surface of thirty elementary fibres for each batch is counted after observation with an optical microscope under polarized light and over a distance of 330 μm.In addition,the area of each of these kink bands is also determined,using ImageJ software following a manual identification of each kink band.The surface tool permits computing the area of the identified defects.2.7.2.Determination of the cross-sectional areas of the elementary fibres prior to tensile test The elementary fibres extracted from each batch are glued at each end to plastic tabs with a light-sensitive glue to prevent the fibre slipping during the tensile test.A gauge length of 12 mm is taken for tensile tests.The measurement of fibre cross-sections is carried out using a device manufactured by the company Dia-Stron called the Fibre Dimensional Analysis System and controlled by the UV Win software also developed by the company.This type of device permits to accurately determine the diameters of the fibres using an “automated laser scanning” method based on the light shadow technique performed using a high-precision laser source and photodetector.The fibres mounted on plastic tabs are positioned in the rotating jaws of the FDAS module and held in position by a pneumatic system.By 360 ◦ rotation of the jaws,the diameter of the fibre is measured over its entire circumference locally.The fibre is then translated and another part of the fibre is scanned over its whole circumference again.This operation can be repeated over the entire length of the sample.In this study,ten measurements are distributed over the 12 mm length of the gauge.As the fibre is rotating,the projected diameters are recorded and the maximum and minimum diameters are extracted to determine the fibre cross section using an elliptical model as recommended for technical fibres by who observed that this approach permits obtaining cross section measurements with a higher accuracy than with other models such as the circular model recommended by the NF 25-501-2 standard.This is due to the fact that hemp fibres are not circular.The measurements are carried out with an accuracy of 0.01 μm.A more detailed description of the device is available in Gr´egoire et al..Tensile tests are carried out on thirty elementary fibres from each batch.The device to apply the tension on the individual fibre was developed by the Dia-Stron,company.This is an automated high-precision extensometer which is equipped with a ±20 N load cell.Displacement is achieved using a step by step motor which permits to control the displacement with an accuracy of 1 μm.This makes the device suitable for fibre breaks with low levels of deformation.

The tests are carried out using a displacement speed of 0.0167 mm/s and a break threshold value of 5 gmf  as recommended by the NF T25-501-2 standard.The deformation selected for Modulus of elasticity corresponds to the one of the Young’s modulus,indoor cannabis grow system at the beginning of the stress-strain curve.The “fineness” of the fibre bundles is determined using a lab scale type device based on a laser scan technology proposed by Itecinnovation company.It consists in cutting the fibres in short length with a guillotine and dispersing them in an alcoholic liquid to prevent their swelling.Fibres are placed in a fluid flow and they are scanned by a laser: when a laser beam illuminates a fibre,a shadow appears on the photodetector.This area is directly proportional to the fibre diameter if one assumes that the fibres are cylindrical.This device,originally developed for wool fibres was modified by the manufacturer and adapted to bast fibres.This device was available at the Terre de Lin company premises.The tests were carried out on batches of 1000 fibres and a distribution can be obtained.The extraction of dew-retted hemp stems on industrial facilities,with process parameters not optimised for hemp,resulted in fibre yields of 9.15 % after scutching and 5.11 % after hackling.After hackling,the long line fibre mass represents in this case only 17 % of the initial fibre mass in the stem.The feed and beating speeds in the industrial scutching module are the ones generally used on flax.These process parameters appear to be un-adapted as very large quantities of fibres fall in the tows.After analysis,one can observe that a very large part of the scutching tow fibres are long line fibres.Scutching tows were taken randomly during the industrial scutching process right below the machines.One can observe in Fig.2a that a large amount of fibre is present.It contributes to about 50 % of the mixture mass.In Fig.2b,the tows,collected at a different moment contain in a vast majority long line fibre.A more complete analysis of the tows,with a large number of collected samples would be necessary to characterise the amounts of long line,short fibres and shives contained in the scutching tows.One can,however,observe that the mass of fibre is very large and can be represented by large quantities of long line fibres that should not fall in the tows.Different hypothesis can be formulated to explain this unwanted phenomenon.The first one is the use of too aggressive process parameters as,on the contrary to what was expected,hemp requires lower compression and beating loads than an equivalent mass of flax.

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Hemp was sown every year in April with the sowing rate of 42 kg of seeds per ha

Posted on August 5, 2022 by hemp2022

Field experiments were conducted in years 2014–2018 on the lignite post-mining area close to Kazimierz Biskupi province Wielkopolska, Poland. The research was financially supported by European Comission LIFE + grant LIFE11ENV/PL/445 and by National Fund for Environmental Protection and Water Management in Warsaw granted to the Institute of Natural Fibres and Medicinal Plants. Before agronomic treatments could be conducted in selected experimental field, they had to be cleared of volunteer weeds and bushes as well as stones. The number of stones made initially the work on the field impossible. After removing the stones, agrotechnical works were carried out, which included disc-harrowing of the field and plowing followed by pre-sowing tillage and application of lime in the dose of 0.25 tons/ha. Liming of the field was carried out only in the first year of the project. Every year mineral fertilization was carried out in accordance with the fertilization plan: nitrogen fertilization at a dose of 150 kg N/ha, phosphorus fertilization at a dose of 150 kg P2O5/ha and potassium fertilization at the dose of 215 kg K/ha. Phosphorus and potassium fertilizers were applied in autumn and nitrogen in spring before sowing of hemp. Every year in October hemp was mowed. Mowing was conducted using a mower pulled by the tractor, equipped with three knives cutting the stem into three sections. This facilitated later plowing the biomass down. Working width of the mower was 4 m and it was able to mow 3− 4 ha/h. In November, plant residues were plowed with 30 cm deep plowing. The costs of all agronomic treatments were estimated at 660 euro per hectar per year. Samples for soil tests were collected annually before the commencement of spring agrotechnical treatments with the use of a soil auger. The field was divided into four sections, five samples were taken from each section. Laboratory tests were performed using accepted Polish standards . Phosphorus and potassium were extracted from soil using Egner-Riehm method and then phosphorus was determined by spectrophotometric method and potassium by flame photometry .

Magnesium was extracted with 0.0125 M CaCl2 solution and determined by atomic absorption spectrometry . The soil pH was determined in 1 N KCl. Micronutrients were extracted with 1 N HCl and manganese, zinc and copper were determined by atomic absorption spectrometry while boron by spectrophotometry . The presented weather pattern data is from the Weather Station in Konin . In the years of experiment the average temperatures during hemp growth season differed only a little with the exception of 2018 – the warmest year in the period of plants emergency. Precipitation in 2017 was significantly higher than in the remaining years of the experiment. Especially June and July 2017 were characterized by a lot of rainfall. The reclaimed layer was very wet due to its limited water permeability. Frequent rainfall had largely suffocated the cultivated hemp. Cannabis grow system plants died in many places due to the lack of oxygen in the soil layer, which was displaced by water . The height of the plants often did not exceed 1 m at that year. Such unfavorable weather conditions led to a reduction in the yield of plants. The results were evaluated statistically with the R statistical software version 4.0.5 . ANOVA tests were used to test main effects of recultivation year. The data from all years were combined and analysed post hoc with Fisher’s LSD test from agricolae package at a significance level α = 0.05. Agrotechnical procedures related to reclamation of the experimental field started in 2013. They consisted of clearing the field of stones, sowing lime and PK fertilization. The aforementioned treatments were designed to initiate the plot reconstruction and preparation for the planned vegetation treatment. The soil depletion with previously conducted industrial activity resulted in low hemp yielding in the first year of the experiment. The average hemp biomass yield was only 1.6 tons/ha . Already in the second year of the project, the annual incorporation of biomass from the first year led to the activation of the soil and a jump of the yield of hemp biomass to 5.3 tons/ha , followed by 5.9 tons/ha in 2016. The highest yield of 6.3 tons/ha was obtained in the last year of experiment. This growth was also influenced by favorable weather conditions favoring the development of the plants in 2018. The increase of the hemp yield was the result of the increase of the plants heigh and the straw width . In the first year of the experiment the average plants heigh was only 56 cm, while on the second year it was higher by 236 % and in 2016 reached the average height of 193 cm.

The straw width on the second and third year of experiment was 3 times bigger than in 2014 . In 2017, hemp crop suffered due to long-lasting intense rainfall. A large amount of precipitation in the period immediately after emergence led to the loss of many plants. It was reported that too much available moisture can limit production or cause failure, particularly in low lying and poorly drained fields . In the case of the reclaimed minesoil, due to the compact, impermeable recultivated layer, even slight rainfall led to the formation of large water stalls . The standing water displaced oxygen from the soil which led to the suffocation of many plants. This lead to the low hemp yield of 3,5 tons/ha and low and thin plants. Every year, the hemp biomass obtained was plowed in, enriching the soil with nutrients. This affected the level of humus in the reclaimed soil. The 2014 yield after plowing in had an impact on the content of nutrients in the soil, which was tested before the commencement of agrotechnical treatments in 2015. The same applies to all years of research. The annual incorporation of plant biomass resulted in a gradual increase in the level of humus in the reclaimed soil . The year 2014 is treated as the starting year in the conducted experiment. In 2015 we did not observe any increase of the organic matter content in the soil and it remained on a very low level of 0,88 %. It was due to the relatively small amount of plant biomass received and plowed in in 2014. Between 2015 and 2016 the increase of the OM was observed as we noted 10 % increase but is was not statistically significant. A statistically significant increase was observed in 2017. The soil survey carried out in 2017 showed a significant increase in the level of humus in the soil also in relation to the initial data from 0,87 % to 2.44 %. In the last year of experiment in 2018 we did not observe the further increase of the OM content but the deviations of the measurements decreased. In this year we did not note the large differences between samles analyzed. It is widely agreed that successful reclamation of lignite mine sites, especially when the topsoil has been removed, depends on the rapid formation of a surface horizon rich in organic matter Humic substances improve the physical properties of mine soils by favouring aggregation, which facilitates aeration and water transport. They also improve the chemical properties of soil by providing buffering capacity and increasing surface area and ion exchange capacity. As a result soils on reclamation sites can become progressively more productive with time . It the case of the presented survey we have observed relatively fast building up of the soil organic matter. Already after four years in the top layer of the studied minesoil the OM reached the level observed in the undisturbed agricultural soils of the region.

It is in line with the other authors reporting that reclaimed minesoils develop recognizable horizonation relatively quickly and effectively sequester carbon . It was reported that a distinct horizon up to 15 cm thick can develop during first 5 years of reclamation and is distinguished from subsoil by the accumulation of SOM, loose soils due to root growth, and soil structure development . The potential of organic matter sequestration in minesoils depends on biomass productivity but also on root development in the subsoil and changes in minesoil resulting of their development . Hemp grown in the optimal soil condition has a well-developed taproot system, growing into the soil to a depth of about 2 m. Duringthe course of the experiment we have observed the changes of hemp root architecture . In the first years the typical tap root was hardly visible. The lateral roots were numerous, but small and thin and outgrown rather the top layer of the minesoil. In later years, the plants began to develop a tap roots, typical for this species, which penetrated well into the soil. The root was still thinner compared to the plants grown on agricultural soils, but the root system looked typical for cannabis. Roots provide a path for movement of carbon and energy to the deeper horizons of the recultivated minesoil. Therefore, cannabis grow lights root production have a direct impact on the amount of organic matter present in the soil . The fine root contributions to SOC range from 33 to 67 percent in forest ecosystems . Balesdent and Balabane calculated that corn roots incorporated 58 percent more carbon than combined incorporation by leaves and stalks. From this perspective, the use of hemp, capable of producing a large amount of above ground biomass and at the same time developing a strong and deeply growing root system, for the rehabilitation of areas poor in organic matter, seems to be justified as deep-rooted plant species have the potential of increasing SOC sequestration by transferring more OM into deeper horizons. In many cases reported in the literature the minesoils formed after lignite mining suffer with low or extremly low pH. It was not observed in our case. During the course of experiment the pH of the minesoil remained alkaline, close to neutral . We have observed slight increase of the soil pH value during the years. Soil pH is one of the main factors determining soil fertility and it may be affected by crop and residue management. Reports on the effect of organic matter addition on soil pH have been contradictory. Some authors have suggested that accumulation of fresh organic matter may be one of the causes of soil acidification while many other reported soil pH increase after OM incorporation .

Our observations are in line with the latter reports. The the exception from this trend was observed in the second year when pH dropped from 7.7 in 2014 to 7.4. This drop was due to the lack of the soil structure typical for the minesoil at the begining of rehabilitation process, resulting with the lack of oxygen in the top layer. These together with the incorporation of the initial amount of the organic matter from the previous year could lead to the anaerobic microbial processes in the soil, production of organic acids and lowering the soil pH. The amount of all four tested macroelements increased during the course of the minesoil reclamation experiment however, the content increase dynamics was different in the case of the analyzed elements . The content of phosphorus and, to some extent, also potassium increased in proportion to the increase in the content of organic matter . At the same time, the magnesium content increased linearly in each year of the experiment, and the changes in the manganese content corresponded to the changes in the soil pH . The content of phosphorus in the tested soil increased with the reclamation carried out. This increase was statistically significant. The level of phosphorus in the reclaimed soil was below the norm, ranging from 101 to 150 mg kg of typical agricultural soil. During first two years it was extremely low . In the third year phosphorus level increased by 39 % and in 2017 by next 42 % reaching 117 mg kg. In the last year of the experiment the phosphorus content did not increase anymore but in the last two years the soil reached the minimal accepted level of 100 mg kg.

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