Antioxidant Activity of Peptides Obtained from Porcine Myofibrillar Proteins by Protease Treatment

TLDR

Hydrolysates from porcine myofibrillar proteins treated with papain or actinase E show strong antioxidant activity in Fe²⁺‑induced linolenic acid peroxidation, DPPH radical scavenging, and metal‑chelating assays. Antioxidant peptides were isolated from the papain hydrolysate by ion‑exchange chromatography followed by ODS‑column HPLC, yielding acidic fractions containing peptides DSGVT, IEAEGE, DAQEKLE, EELDNALN, and VPSIDDQEELM. The hydrolysates exhibited greater antioxidant activity at pH 7.1 than at pH 5.4, with papain hydrolysate matching vitamin E at pH 7.0; the acidic fraction was most active, and among isolated peptides, DAQEKLE showed the highest activity. Keywords: antioxidant, papain, myofibrillar protein hydrolysate, peptide.

Abstract

Hydrolysates obtained from porcine myofibrillar proteins by protease treatment (papain or actinase E) exhibited high antioxidant activity in a linolenic acid peroxidation system induced by Fe2+. Hydrolysates produced by both papain and actinase E showed higher activities at pH 7.1 than at pH 5.4. The antioxidant activity of the papain hydrolysate was almost the same as that of vitamin E at pH 7.0. These hydrolysates possessed 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and chelating activity toward metal ions. Antioxidant peptides were separated from the papain hydrolysate by ion exchange chromatography. The acidic fraction obtained by this method exhibited higher activity than the neutral or basic fractions. Antioxidant peptides in the acidic fraction were isolated by high-performance liquid chromatography on an ODS column and shown to possess the structures DSGVT, IEAEGE, DAQEKLE, EELDNALN, and VPSIDDQEELM. The DAQEKLE peptide showed the highest activity among these peptides. Keywords: Antioxidant; papain; myofibrillar protein hydrolysate; peptide