Protease from Aspergillus oryzae : Biochemical Characterization and Application as a Potential Biocatalyst for Production of Protein Hydrolysates with Antioxidant Activities

Abstract

This study reports the biochemical characterization of a protease from Aspergillus oryzae LBA 01 and the study of the antioxidant properties of protein hydrolysates produced with this protease. The biochemical characterization showed that the enzyme was most active over the pH range 5.0–5.5 and was stable from pH 4.5 to 5.5. The optimum temperature range for activity was 55–60°C, and the enzyme was stable at temperatures below 45°C. The activation energy ( E a ) for azocasein hydrolysis and temperature quotient ( Q 10 ) were found to be 37.98 kJ mol −1 and 1.64–1.53 at temperature range from 30 to 55°C, respectively. The enzyme exhibited t 1 / 2 of 97.63 min and a D value of 324.31 at the optimum temperature for activity (57.2°C). Protease from A. oryzae LBA 01 was shown as a potentially useful biocatalyst for protein hydrolysis, increasing the antioxidant activities of soy protein isolate, bovine whey protein, and egg white protein from 2.0- to 10.0-fold.