Purification and identification of novel antioxidant peptides from enzymatic hydrolysate of chickpea (Cicer arietinum L.) protein concentrate

Enzymatic hydrolysis of chickpea protein concentrate (CP) by Alcalase (R) and some physiochemical and antioxidant properties of the resulting hydrolysate (CPH) were characterised. CPH displayed higher antioxidant activity than CP. This hydrolysate was fractionated by size exclusion chromatography on a Sephadex G-25 into four major fractions (Fra.I, Fra.II, Fra.III, and Fra.IV). Fraction III, which exhibited the highest DPPH scavenging activity (54% at 1 mg/ml), was then fractionated by reversed-phase high performance liquid chromatography (RP-HPLC). Eleven antioxidant fractions were isolated and two peptide subfractions show antioxidant activity (P3 and P8). The P8 displayed the highest DPPH radical-scavenging activity (67%; at 200 mu g/ml) among these peptides subfractions. The molecular masses and amino acids sequences of the purified peptides were determined using ESIMS and ESIMS/MS, respectively. Their structures were identified as Asp-His-Gly and Val-Gly-Asp-Ile. These peptides did not show haemolytic activity towards bovine erythrocytes. The results suggest that CPH are good source of natural antioxidants. (C) 2014 Elsevier Ltd. All rights reserved.