PURIFICATION AND CHARACTERIZATION OF ANTIOXIDANT PEPTIDES FROM SOY PROTEIN HYDROLYSATE

Abstract

Soy protein hydrolysates (SPH) were obtained by Alcalase hydrolysis of soy protein. Antioxidant activity of SPH was measured with a lipid peroxidation inhibitory activity and lipid oxidation was evaluated by measuring the thiobarbituric acid (TBA) and peroxide value. The potent antioxidant peptide was purified using ultrafiltration and consecutive chromatographic methods including FPLC and reverse-phase high-performance liquid chromatography. The antioxidant activity having a specific activity of 108.13%/µg for TBA method was enhanced 67.6-fold compared with SPH. In the amino acid composition of the final potent antioxidant peptide, hydrophobic amino acids were the most abundant amino acids and among them phenylalanine was especially abundant. PRACTICAL APPLICATIONS Soybean is important because of not only its multiple health-promoting properties but also its role as a useful source for producing biological active peptides. Enzymatic hydrolysis has been employed in order to produce the active peptide from various protein sources because of its naturalness and safety. In this paper, the potent antioxidant peptide was purified by an ultrafiltration and a series of chromatography from soy protein hydrolysates (SPH) obtained by Alcalase treatment. It is expected that the SPH with enhanced antioxidant activity could be used in a wide range of foods as a useful functional food ingredient.