Antioxidant properties of ultrafiltration membrane fractions obtained from fenugreek (Trigonella foenum-graecum) proteins hydrolysates

Abstract

Introduction. Legumes may be a potential source of biopeptides. These biopeptides can be released from proteins by controlled enzymatic hydrolysis. The obtained hydrolysates consist of a peptides mixture. Objective . This study was conducted to eva-luate the in vitro antioxidant activity of fenugreek protein hydrolysates, and their fractions. Material and methods . Fenugreek proteins were hydrolyzed by two endopeptidases: Esperase and Purafect. Fenugreek proteins hydrolysatesby Esperase- (EFPH),and by Purafect (PFPH) were then fractionated by membrane ultrafiltration at the molecular cutoff thresholds of 30, 10 and 5 kDa. The antioxidant activity of obtained hydrolysates and fractions was essayed, and compared by two antioxidant test: diphenylpicrylhydra-zyl scavenging activity, and ferric reducing activity power. Results . EFPH exhibited higher antioxidant properties compared to PFPH. Among the fractions, those <5kDa and >30kDa showed the best antioxidant activities. However, the fractions showed antioxidant properties less than or equal to those of the hydrolysates. Conclusion . Fenugreek protein hydrolysates have antioxidant properties. Moreover, these properties are not significantly improved after fractionation.