Rice Bran Protein Hydrolysate and Its Antioxidant Activity

Abstract

Rice bran was generally used as animal feed, while it contains many potential compounds. With hydrolysis reaction, small peptides can be obtained from rice bran protein, in which it showed higher antioxidative activity. The antioxidative activity of rice bran protein hydrolysate from fractionated rice bran was studied in this work. Albumin, globulin, glutelin and prolamin protein fractions were fractionated by its solubility and hydrolyzed with two type of enzyme, pepsin and proteaseM, at various digestion times. Albumin fraction showed high degree of hydrolysis for both enzyme hydrolysis. Protease M digestion showed different digesting ability towards different protein fractions, in which it has low impact on glutelin and prolamin fraction. Pepsin hydrolysis resulted in higher degree of hydrolysis compared to protease M digestion. After 30 minutes of hydrolysis time, hydrolysis reaction slowed down and antioxidant activity remained constant in pepsin hydrolysis. Prolamin and glutelin in pepsin digestion showed the highest activity of ABTS radical scavenging (4.02 mM and 3.93 mM TEAC) compared to the other hydrolysates. Rice bran protein hydrolysates showed much higher in antioxidant activity compared to the undigested rice bran protein which can be explained antioxidant activity derived from rice bran peptides