ANTIOXIDANT ACTIVITY OF HYDROLYSATES AND PEPTIDE FRACTIONS OF PORCINE PLASMA ALBUMIN AND GLOBULIN

To investigate the antioxidant properties, hydrolysates of porcine plasma albumin and globulin were prepared through hydrolysis by Alcalase and were separated into five groups according to molecular weight (MW) by sequential ultrafiltration. The reducing power (RP), lipid peroxidation inhibitory activity and radical scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl and superoxide of these fractions were evaluated. The RP of hydrolysates increased initially and then decreased during hydrolysis. Peptide fractions with smaller MW (< 3 kDa) had higher RP compared with larger MW fractions. Peptide fractions had better lipid peroxidation inhibitory activity compared with vitamin E. Radical scavenging activity of DPPH, hydroxyl and superoxide of albumin of small MW (< 3 kDa) was higher than that of globulin (P < 0.05). Hydrolysates and peptide fractions of small MW of the two proteins have better antioxidant potential.