Identification and hydrolysis kinetic of a novel antioxidant peptide from pecan meal using Alcalase

In this study, the hydrolysis of a pecan protein isolate (PPI) with Alcalase was carried out to generate antioxidant peptides. We proposed a kinetic model to illustrate the enzymolysis process of PPI, which was found suitable for depiction of the kinetic behavior for PPI hydrolysis by Alcalase. The PPI hydrolysis products were gradually fractionated by ultrafiltration through cut-off membranes with molecular weights of 10, 5 and 3 kDa and their antioxidant activities were evaluated in vitro. Further, the strongest antioxidant fraction (< 3 kDa) and novel antioxidative peptide were successfully purified. The amino acid sequence of the purified peptide was identified as LAYLQYTDFETR. The purified fraction exhibited appreciable scavenging activities on ABTS radical (67.67%), DPPH radical (56.25%) and hydroxyl radical (47.42%) at 0.1 mg/mL. The results suggested that this novel peptide may serve as a potential antioxidant and it should be evaluated for development of functional foods and pharmaceuticals products.