The Seed of Industrial Hemp (Cannabis sativa L.): Nutritional Quality and Potential Functionality for Human Health and Nutrition

Hempseeds, the edible fruits of the Cannabis sativa L. plant, were initially considered a by-product of the hemp technical fibre industry. Nowadays, following the restorationing of the cultivation of C. sativa L. plants containing an amount of delta-9-tetrahydrocannabinol (THC) <0.3% or 0.2% (industrial hemp) there is a growing interest for the hempseeds production due to their high nutritional value and functional features. The goal of this review is to examine the scientific literature concerning the nutritional and functional properties of hempseeds. Furthermore, we revised the scientific literature regarding the potential use of hempseeds and their derivatives as a dietary supplement for the prevention and treatment of inflammatory and chronic-degenerative diseases on animal models and humans too. In the first part of the work, we provide information regarding the genetic, biochemical, and legislative aspects of this plant that are, in our opinion essential to understand the difference between “industrial” and “drug-type” hemp. In the final part of the review, the employment of hempseeds by the food industry as livestock feed supplement and as ingredient to enrich or fortify daily foods has also revised. Overall, this review intends to encourage further and comprehensive investigations about the adoption of hempseeds in the functional foods field.

Bamboo fibres sourced from three global locations: A microstructural, mechanical and chemical composition study

More than 1200 bamboo species are known; therefore, the question arises which species are suited for composites and which microstructural characteristics of the plant are decisive. Three different bamboo species are considered, each of two ages. Technical fibre tensile tests and impregnated fibre bundle tests were performed to characterize the fibres and maceration was applied to determine the length over diameter ratio of the elementary fibres. From the impregnated fibre bundle tests it is concluded that the stiffness of bamboo fibres from tropical species considered in this research is unaffected by the species nor the age of the plant. The strength is more affected by the region of growth, with the temperate bamboo species having lower strength as a result of a lower length over diameter ratio of the elementary fibre. Chemical analysis helped to investigate the age difference and it can be stated that the fibres are mature within one growing season.

In-depth study of the microstructure of bamboo fibres and their relation to the mechanical properties

The mechanical properties of bamboo technical fibre, from the species Guadua angustifolia, have been studied showing values of strength up to 800 MPa and E-modulus up to 43 GPa, proving their adequate tensile properties that make this natural fibre suitable as reinforcement in composite materials. To fully explore the good mechanical properties and to make an adequate use of this new reinforcement, it is indispensable to comprehensively understand the fibre behaviour as a function of the microstructure. Microscopic observations have provided us with an extensive knowledge of the complex microstructure of this natural fibre from the macroscale down to the microscale level where different features like the distribution of the elementary fibres within the fibre bundle, dimensions and layering pattern of the elementary fibres and the main microfibrillar angles could be measured. The Young’s modulus of the elementary fibre is analysed based on the micromechanics of composite materials, commonly used for unidirectional short fibre composites, and the fibre microstructure. The predicted results are in reasonable agreement with experimental data, showing the appropriateness of the model for describing the elementary fibre stiffness. Also, the failure modes of single fibres after tensile testing are analysed by microscopic observations, to have an indication of the stress development in the elementary fibres and the different failure mechanisms.