Nutritional composition, ultrastructural characterization, and peptidome profile of antioxidant hemp protein hydrolysates

Hemp is the term commonly used to refer to the variety of Cannabis sativa L. cultivated for industrial purposes. The seeds have gained interest in recent years as functional foods due to their nutritional composition and high content of protein and bioactive compounds. In this study, ten hemp protein hydrolysates (HPHs) were obtained by enzymatic hydrolysis with Alcalase and Flavourzyme from hemp protein isolate (HPI) and their antioxidant properties (DPPH radical scavenging activity, beta-carotene activity and ferric ion reducing antioxidant power (FRAP)) were evaluated. Shorter peptide sequences, mainly obtained with Flavourzyme, were found to react with free radicals more easily. The peptidome of all the hydrolysates was characterized, identifying, and quantifying the peptides. Furthermore, 19 unique peptides were assessed by in silico tools to hypothesize those that could be responsible of the bioactivity reported for the hydrolysates. From the identified peptides, based on the molecular features and the predictions, the peptides KNAIYTPH, EERPGHF, and KNGMMAPH, among others, are proposed to be highly contributing to the antioxidant activity of the hydrolysates.