Hemp macromolecules: Crafting sustainable solutions for food and packaging innovation

Axentii M., Codină G.G.

Plant-based proteins, like those derived from hemp and rapeseed can contribute significantly to a balanced diet and meet human daily nutritional requirements by providing essential nutrients such as protein, fiber, vitamins, minerals, and antioxidants. According to numerous recent research papers, the consumption of plant-based proteins has been associated with numerous health benefits, including a reduced risk of chronic diseases such as heart disease, diabetes, and certain cancers. Plant-based diets are often lower in saturated fat and cholesterol and higher in fiber and phytonutrients, which can support overall health and well-being. Present research investigates the nutritional attributes, functional properties, and potential food applications of hemp and rapeseed protein for a potential use in new food-product development, with a certain focus on identifying anti-nutritional factors and bioactive compounds. Through comprehensive analysis, anti-nutritional factors and bioactive compounds were elucidated, shedding light on their impact on protein quality and digestibility. The study also delves into the functional properties of hemp and rapeseed protein, unveiling their versatility in various food applications. Insights from this research contribute to a deeper understanding of the nutritional value and functional potential of hemp and rapeseed protein, paving the way for their further utilization in innovative food products with enhanced nutritional value and notable health benefits.

Joseph D.P., Rajchakit U., Pilkington L.I., Sarojini V., Barker D.

Surface functionalisation of natural materials to develop sustainable and environmentally friendly antimicrobial fibres has received great research interest in recent years. Herein, chitosan covalent conjugation via aryl-diazonium based chemistry onto Phormium tenax fibres (PTF) and hemp hurds (HH) was investigated. PTF are fibres derived from Harakeke/New Zealand flax, an indigenous and abundant plant source of leaf fibres, which served as an important 19th century export commodity of New Zealand. HH are obtained as a by-product from the hemp (Cannabis sativa) industry and find applications as traditional construction material, animal bedding, chemical absorbent, insulation, fireboard etc. This study reports aryl-diazonium covalent attachment of chitosan and PD13 (6-O-(3-(2-(N,N-dimethylamino)ethylamino)-2-hydroxypropyl)chitosan), a chitosan derivative with improved antibacterial activity, on to PTF and HH. The modification was confirmed using FTIR, XPS, SEM and water contact angle studies. Comparison of aryl-diazonium versus the use of succinic anhydride bridging for chitosan attachment was also investigated, with the diazonium method giving improved results. The treated PTF and HH fibres had good antibacterial activity against Staphylococcus aureus and this study contributes to the development of sustainable antibacterial fibres using bio-based materials.

Feng Y., Xu T., Shi X., Hu Y., Ni C., Chu Z., Yang Z.

Ecologically feasible strategies for constructing superhydrophobic surfaces offer versatile applications in waterproofing, self-cleaning, selective absorption, and corrosion protection. Herein, we prepared low-surface-energy branched-chain-enriched micronanorod (F@SiO2@MNC) by hydrolyzing silane coupling agent and modifying fluoropolymer using micro-nanocellulose extracted from waste straw (Chinese hemp). These rods were sprayed and adhered to various substrates precoated with a binder, resulting in superhydrophobic surfaces. F@SiO2@MNC addition allowed for the formation of stable spherical liquid droplets when in contact with different types of aqueous liquids. Furthermore, these surfaces demonstrated excellent self-cleaning, robustness, abrasion resistance, UV resistance, cycling stability, and other multifunctionalities. They significantly enhanced the mechanical properties of filter paper, effectively separated oil water mixtures, and improved the corrosion resistance of metals. Our proposed strategy represents a novel approach for developing multifunctional coatings assembled from micronanocellulose.

Chaowana P., Hnoocham W., Chaiprapat S., Yimlamai P., Chitbanyong K., Wanitpinyo K., Chaisan T., Paopun Y., Pisutpiched S., Khantayanuwong S., Puangsin B.

Recent concerns regarding climate change and rising energy costs have dramatically increased interest in using alternative energies, especially biomass energy which is carbon neutral. Hemp is among the fastest-growing plants with unique fiber characteristics. The objective of this study was to investigate the physical and chemical properties of hemp stalks of seven different clones and to assess their feasibility as a sustainable bioenergy resource. Seven clones (KU03, KU18, KU27, KU45, KU49, RPF1, and RPF2) of four-month-old hemp (Cannabis sativa) were used in this work. Physical properties, volatile content, fixed carbon, ash content, calorific value, chemical composition, ash composition, and metal element of the samples were investigated. The results revealed that hemp stalk had desirable fuel characteristics with high volatile substance, high heating value, low ash content, very low nitrogen content, and non-detectable sulfur. Selecting well-adapted clones and appropriate technology which can convert the hemp stalks to suitable bioenergy forms are important aspects of bioresource management. Based on our findings, some selected hemp clone biomass possessed excellent characteristics and great potential to be used as raw material for bioenergy production.

Karabulut G., Kahraman O., Pandalaneni K., Kapoor R., Feng H.

With the global population on the rise, challenges in meeting protein demands are amplified by recent crises, prompting a swift shift to alternative protein sources due to disruptions in the supply chain. Plant-based proteins are gaining momentum due to economic, cultural, and environmental considerations, aligning with the preference for sustainable diets and resulting in more affordable plant-based products. The distinction between drug and industrial hemp fuels demand for its nutritional value, digestibility, low allergenicity, and bioactive properties. Industrial hempseed, featuring minimal Δ9-Tetrahydrocannabinol (THC) content (

Liao M., Pan Y., Fu X., Wu S., Gan S., Wu Z., Zhao H., Zheng W., Cao Y., Zhou W., Dong X.

Bacterial and fungal contamination have become major factors in fruit spoilage and damage, posing a potential risk to human health. In this work, polylactic acid (PLA) nanofibers combined with Ag2O-hemp fibers for a good antimicrobial effect were developed and applied to antimicrobial fruit fresh-keeping packages. The results of molecular simulation calculations showed that the strength of hydrogen bonds between Ag2O and hemp fibers reached 45.522 kJ·mol-1, which proved that Ag2O and with hemp fibers formed a stable deposition. The Ag2O-hemp fibers modified electrospun polylactic acid nanofibrous composite film exhibited favorable mechanical properties. The tensile strength reached 5.23 ± 0.05 MPa and the elongation at break reached 105.56 ± 3.95 %. The obtained nanofibrous composite film has good antibacterial activity against E. coli, S. aureus, A. niger, and Penicillium, which indicated that they could effectively inhibit the growth of bacteria and fungi. The cell experiments proved that the nanofibrous composite film had good biocompatibility with a cell survival rate of 100 %. The experimental results on the fresh-keeping of red grapes showed that the PLA nanofibrous composite film modified by the Ag2O-hemp fibers could effectively prolong the spoilage time of red grapes at room temperature. Compared with the blank group, the freshness period of PLA nanofiber film modified by Ag2O-hemp fibers could be extended for more than 5 days. The hardness of 15 days (1.94 ± 0.19 × 105 Pa) was basically the same as that of 1 day (2.05 ± 0.06 × 105 Pa). The results were superior to commercially available PE preservation films. The above research results indicated that the Ag2O-hemp fibers modified PLA nanofibrous composite film had potential application prospects in the field of fruit fresh-keeping package.

Bahsaine K., El Allaoui B., Benzeid H., El Achaby M., Zari N., Qaiss A.E., Bouhfid R.

Bio-nanocomposite were developed using a blend of PVA, chitosan, and cellulose nanocrystals extracted from hemp. The inclusion of CNCs up to 5% improved the mechanical properties, maintained transparency, and reduced gas transmission rate.

Popp M., Latta S., Nguyen B., Vincenzi C., Tosti A.

Cannabinoid products have been studied in the treatment of various dermatologic conditions. We searched PubMed/MEDLINE for articles published before 1 February 2023 that described the use of cannabinoids in the management of hair, scalp, and skin conditions, identifying 18 original articles that encompassed 1090 patients who used various forms of cannabinoid products. Where specified, topical cannabidiol (CBD) was the most commonly utilized treatment (64.3%, 173/269), followed by oral dronabinol (14.4%, 39/269), oral lenabasum (14.1%, 38/269), and oral hempseed oil (5.9%, 16/269). Using the GRADE approach, we found moderate-quality evidence supporting the efficacy of cannabinoid products in managing atopic dermatitis, dermatomyositis, psoriasis, and systemic sclerosis and moderate-quality evidence supporting a lack of efficacy in treating trichotillomania. There was low to very low quality evidence supporting the efficacy of cannabinoid products in managing alopecia areata, epidermolysis bullosa, hyperhidrosis, seborrheic dermatitis, and pruritus. Our findings suggest that cannabinoids may have efficacy in managing symptoms of certain inflammatory dermatologic conditions. However, the evidence is still limited, and there is no standardized dosage or route of administration for these products. Large randomized controlled trials and further studies with standardized treatment regimens are necessary to better understand the safety and efficacy of cannabinoids.

An N., Hu J., Ding Y., Sheng P., Zhang Z., Guo X.

Three instant pH-responsive intelligent chromogenic indicator films were fabricated by ionic liquid regenerated cellulose and introduction of shikonin with solution-casting method. The sensitive color change of the indicator film from reddish purple to light bluish purple could be observed in three cellulose-based films as the pH increased. Furthermore, the stimuli-responsive color change of hemp/shikonin film is more pronounced in the narrow region from pH 5.5 to 8.5. During real-time monitoring of shrimp freshness, the utilization of hemp/shikonin indicator film revealed a highly responsive alteration in discoloration from shrimp fresh (pH = 6.7) to spoiled (pH = 7.2), without noticeable change on the appearance of the shrimp visually. Besides, the shikonin-added indicator film exhibited notable UV-light barrier property and free radical scavenging activity, as well as greater thermal stability and mechanical strength. Due to its versatility and pH stimuli-responsive color changing, this novel indicator film has great application potential in smart food packaging.

Triesch N., Vijayakumar N., Weigel S., These A.

Lamsaf H., Singh S., Pereira J., Poças F.

Hemp (Cannabis sativa) stalk fibres from industry residues were incorporated into polybutylene adipate terephthalate, a synthetic biodegradable polyester, to produce films and paper coatings. The lignocellulosic components and the chemical composition of the fibres were analysed, and the results highlight the bioactivity due to cannabinoids, alkanoids, and lignin, among others, making the fibres attractive for active food packaging. The incorporation, without chemical modification, of 2% (w/w) hemp in the PBAT matrix increased the water vapour permeability of PBAT to around 22%. The impact on mechanical properties was determined, and the results show that the PBAT/hemp film is less stretchable but stronger than the pure PBAT film. The incorporation of hemp enhanced significantly the compostability of PBAT. The PBAT/hemp films and paper coatings composted two times faster than those using pure PBAT.

Gheribi R., Taleb Y., Perrin L., Segovia C., Brosse N., Desobry S.

The use of bioresourced packaging materials is an interesting solution for ecological issues. This work aimed to develop novel chitosan-based packaging materials reinforced with hemp fibers (HF). For this purpose, chitosan (CH) films were filled with 15%, 30%, and 50% (w/w) of two kinds of HF: Untreated fibers cut to 1 mm (UHF) and steam exploded fibers (SEHF). The effect of HF addition and HF treatments on chitosan composites was studied in terms of mechanical properties (tensile strength (TS), elongation at break (EB), and Young’s modulus (YM)), barrier properties (water vapor (WVP) and oxygen permeabilities), and thermal properties (glass transition (Tg) and melting temperatures (Tm)). The addition of HF, whether untreated or steam exploded, increased the TS of chitosan composites by 34–65%. WVP was significantly reduced by the addition of HF but no significant change was observed for O2 barrier property, which was in the range between 0.44 and 0.68 cm3·mm/m2·d. Tm of the composite films increased from 133 °C for CH films to 171 °C for films filled with 15% SEHF. However, no significant modification was observed for Tg (105–107 °C). The present study showed that the developed biocomposites had improved properties, mainly the mechanical resistance. Their use in food packaging will help industrials the move toward a sustainable development and circular economy.

Sukhavattanakul P., Thanyacharoen T., Chuysinuan P., Techasakul S., Ummartyotin S.

Xanthopoulou E., Chrysafi I., Polychronidis P., Zamboulis A., Bikiaris D.N.

The exploitation of natural fibers to reinforce polymers is a promising practice. Thus, biocomposites have gained increased attention in automotive, construction, and agricultural sectors, among others. The present work reports the reinforcement of recycled high-density polyethylene (r-HDPE) with hemp fibers to afford composite materials as sustainable analogues to conventional wood/plastic composite (WPC) products. HDPE bottles (postconsumer waste) were used as r-HDPE and further reinforced by the addition of hemp fibers. For the synthetic part, thirteen composite materials with different filler concentrations (10–75% wt. in hemp fibers) using either Joncryl or polyethylene-grafted maleic anhydride (PE-g-MA) as compatibilizers were prepared via melt mixing. Materials with good integrity were obtained with a fiber load as high as 75% wt. The structural, thermal, mechanical, and antioxidant properties of the r-HDPE/hemp composites were evaluated using multiple complementary characterization techniques. Stereoscopic microscope images demonstrated the satisfactory dispersion of the hemp fibers into the polymeric matrix, while scanning electron microscopy microphotographs revealed an improved adhesion between the filler and the polymeric matrix in the presence of compatibilizers. The incorporation of hemp fibers contributed to the improvement of the elastic modulus of the composites (almost up to threefold increase). The results showed that as the hemp fiber content increased, the antioxidant properties as well as the degradability of the composites increased. It is noteworthy that composites containing 75% wt. hemp fibers neutralized 80% of 2,2-diphenyil-1-picrylhydrazyl radicals within 45 min (DPPH assay). In conclusion, the present research work demonstrates that thermally recycled HDPE reinforced with biomass fibers received from agricultural waste is a valid alternative for the preparation of commodity products with an eco-friendly character compared to conventional wood/plastic composites.

Sunoj Valiaparambil Sebastian J., Dong X., Trostle C., Pham H., Joshi M.V., Jessup R.W., Burow M.D., Provin T.L.

Hemp (Cannabis sativa L. ssp. sativa) has a long history of domestication due to its versatile use. Recently, different sectors in the economy are investigating hemp cultivation to increase agronomic production and to limit delta-9-tetrahydrocannabinol (THC). Despite the rapid growth of hemp literature in recent years, it is still uncertain whether the knowledge gained from higher latitude regions is applicable to low latitude and tropical regions where hemp has not been grown traditionally. This review provides a comprehensive and updated survey of hemp agronomy, focusing on environmental and management factors influencing the growth and yield of hemp, methods of cannabinoids detection and quantification, and hemp breeding. This review suggests that some previous claims about hemp as a low input crop may not hold true in low-latitude regions. Additional research strategies, such as the integration of experimentation and modeling efforts, are encouraged to hasten new discoveries. Furthermore, to effectively increase the outputs of value products (cannabinoids, seeds, fiber and biomass, etc.) while limiting the THC level, new collaborations between hemp agronomists and economists may streamline the production process by increasing the efficiency of the total production system of hemp as a multifaceted crop.

Abbel R., Risani R., Nourtier M., Donaldson L., Brunschwig C., Mayer-Laigle C., Bridson J.H., Thumm A., Dickson A., Murray R., Harris J., Beaugrand J., Hill S.

Applying coatings of paraffins and other synthetic waxes is a common approach to impart hydrophobic properties to fibres and thus control their surface characteristics. Replacing these fossil-based products with alternatives derived from renewable resources can contribute to humankind’s transition to a sustainable bioeconomy. This study presents the coating of hemp fibres with waxes extracted from pine bark as an exemplar application. Two bio-based emulsifiers were used to prepare wax emulsions suitable for a dry blending process. The coatings on the fibres were characterised, quantified, and visualised using a combination of spectroscopic and microscopic techniques. Confocal fluorescence microscopy was an excellent tool to investigate the spatial distribution of the pine bark waxes on the fibre surfaces. While successful deposition was demonstrated for all tested formulations, coating homogeneity varied for different emulsifiers. Compounding the hemp fibres with a bio-based polyester resulted in the substantial improvement of the mechanical behaviour. However, the presence of a wax coating on the fibres did not lead to a significant change in mechanical properties compared to the controls with uncoated fibres. Optimising the composite chemistry or adjusting the processing conditions might improve the compatibility of the hemp fibres with the matrix material, resulting in enhanced mechanical performance.