Hemp Seed as a Source of Food Proteins

Abstract

The galloping population growth is leading to a significant increase in the protein demand. Conventional protein sources, particularly those of animal origin, will no longer be sufficient to meet this demand. The use of plant proteins, less costly in terms of resources and with a much lower environmental impact, is an interesting alternative to meet future societal and environmental challenges. Hemp seed is an undervalued co-product resulting from the cultivation of industrial hemp. This plant resource has significant contents in protein and oil of nutritional value, about 26% and 36% respectively, that may help to meet the challenges of sustainable food. The specific valorization of hemp proteins for human consumption is a recent issue. Through this chapter, we showed the current state of knowledge on hemp proteins in terms of composition, nutritional aspect, extraction, and physicochemical, functional and biological properties. Different extraction routes have been proposed to recover the main hemp protein fractions from oil press cakes in general. Extraction yields generally vary from 34% to 51%, and the protein purity of the resulting protein isolates from 87% to 94%. The proteins, usually extractible from hemp meal, belong to the globulin and albumin families. Most of hemp protein isolates contain predominantly globulins, mainly the 11S edestins. The hemp proteins have an interesting essential amino acid profile and have a high digestibility of about 90%. Many authors have highlighted that hemp protein hydrolysates possess a wide range of health biological activities such as antioxidant properties, metal chelation, antihypertensive, hypoglycemic properties… Hemp proteins also have techno-functional properties such as gelling, emulsifying and foaming properties adapted to the development of new plant-based foods. Different treatments of hemp proteins can improve their functional properties, such as enzymatic and chemical modifications or pH- and heat-induced denaturation. Despite limited solubility, hemp protein ingredients represent an alternative to current cereal and legume protein materials in human diet in the future.