The seed of industrial hemp (Cannabis sativa L.): Nutritional Quality and Potential Functionality for Human Health and Nutrition

Abstract

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.

Keywords: Cannabis sativa L. legislation; THC; antinutritional compounds; bioactive peptides; hempseed dietary supplementation; hempseed minerals; hempseed oil; hempseed proteins; hempseed-based food; phenylpropionammides.

Figure 1

The manifold applications of hemp plant: virtually, each part of this plant can be used in a specific industrial field. The seeds can be used in the food, feed, and cosmetical field as whole or dehulled, or it may be subjected to a cold press process to obtain an oil used in the food and cosmetic industries. From the stem, it is possible to obtain both shives and fibre, useful for animal, building, paper and textile applications. The hemp root system is highly developed in comparison to other herbaceous plants, and this feature is suitable for the phytoremediation of soil from heavy metals. Hemp flowers can be used for ornamental purposes or to obtain products of cosmetic and pharmaceutical interest, such as essential oils composed by delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) pure extracts.

Figure 2

The cannabinoid synthetic pathway: cannabigerolic acid (CBGA) is the common precursor of all main cannabinoids. It is synthesized through an alkylation of the phenolic moiety of olivetolic acid with the terpenoid component of geranyl pyrophosphate (GPP). The reaction is catalysed by a geranylpyrophosphate:olivetolate geranyltransferase (GOT). Olivetolic acid is originated in the cytosolic polyketide pathway through an aldol condensation of hexanoyl-Coenzyme A (CoA) with three molecules of malonyl-CoA, that is catalysed by the polyketide synthase (PKS) enzyme in the presence of olivetolic acid cyclase (OAC). The GPP is synthesized by the plastidial methylerythritol phosphate (MEP) pathway. In the cytosol, CBGA is converted into the acidic form of the three main cannabinoids, tetrahydrocannabinol acid (THCA) that in the acidic form has no psychoactive activity, cannabidiolic acid (CBDA) and cannabichromenic acid (CBCA). GPS: geranyl pyrophosphate synthase; IPP: isopentenyl diphosphate; OAC: olivetolic acid cyclase.

Figure 3

The main points of the legislation about C. sativa L. (industrial hemp) cultivation in the US, Canada, and the EU with a focus on the Italian Republic among the EU states. The red line separates the legislation related to the prohibition of C. sativa L. cultivation (left part of the red line) from that allowed the reintroduction of growing of this crop (right part of the red line). For more details, see Section 2.3. US: United States; UN: United Nations; THC: delta-9-tetrahydrocannabinol; EU: European Union; USDA: United Stated Department of Agricultural.