Chapter 7 - Hemp Seed (Cannabis sativa L.) Proteins: Composition, Structure, Enzymatic Modification, and Functional or Bioactive Properties

Abstract

Hemp (Cannabis sativa L.) is a source of nutritious seeds that have been used as human food for thousands of years. The seeds contain nonmedicinal levels (<0.3%) of the psychoactive compound called δ-9-tetrahydrocannabinol (THC) and, therefore, are different from medicinal marijuana. Currently, hemp seed is processed mainly by mechanical pressing to extract the valuable oil, while the residue is used to produce various protein-rich food products. Hemp seed contains the salt-soluble globulins or edestin (~75%) and the water-soluble albumin (~25%) as the main storage proteins. Hemp seed proteins have a high level of arginine and a sulfur-rich protein fraction, two unique features that impart high nutritional values. Functional property evaluations have shown that hemp proteins form high-quality emulsions with oil droplet sizes similar to those of milk-based emulsions. A novel hemp seed protein concentrate has been shown to have >70% solubility at pH 4.0–6.0, whereas most plant proteins are typically insoluble. Addition of hemp seed protein to polycystic kidney disease rat diet led to reduced pathological intensity of renal disease and amelioration of associated cardiovascular impairment. Moreover, hemp seed enzymatic hydrolysates have proven effective during in vitro and in vivo tests as antioxidant and antihypertensive agents. Therefore, hemp seed proteins and hydrolysates have the potential to be used as ingredients to formulate functional foods.