Physicochemical, functional and in vitro bioactive properties of hempseed (Cannabis sativa) protein isolates and hydrolysates.

Abstract

Apart from the nutritional importance of proteins, their physicochemical, functional and bioactive properties are dependent on their structure as well as their resultant interactions with other proteins, water and lipids. We investigated the physicochemical and functional properties of hempseed protein isolate as well the bioactive properties of hemp seed protein hydrolysates (HPH) using antioxidant and antihypertensive assays. The results show that molecular mass decreased with increase in time of hydrolysis. Alcalase treated HPH had an increase in surface hydrophobicity. Increase in hydrolysis time increased protein solubility and water holding capacity of HPH, while foaming and fat absorption capacity decreased as time of hydrolysis increased. The <3 kDa permeates of thermolysin hydrolysate had the highest ACE-inhibition activity, while the <5 kDa permeates of alcalase hydrolysates had the highest renin inhibition value. The various fractions showed low scavenging activity of 1,1–diphenyl-2-picrylhydrazyl, while the superoxide radical scavenging activities were weak to nil. The three various fractions of thermolysin treated hydrolysates displayed the strongest chelating activity. For ferric reducing activities, <5 kDa thermolysin fraction was relatively high when compared to glutathione. The work concluded that HPH can be used not only as a source of nutrients but also as a functional ingredient in food systems as well as therapeutic agent against chronic diseases such as hypertension and oxidative stress-related disorders.