Value-added subcritical water hydrolysate from rice bran and soybean meal

Abstract

New value-added product was derived from agricultural by-products: rice bran and soybean meal by means of subcritical water (SW) hydrolysis. The effect of temperature (200–220 °C), reaction time (10–30 min), raw material-to-water weight ratio (1:5 and 2:5), was determined on the yields of protein, total amino acids, and reducing sugars in the soluble products. The suitable hydrolysis time was 30 min and the proper weight ratio of the raw material-to-water was 1:5. The reaction temperature suitable for the production of protein and amino acids was 220 °C for raw and deoiled rice bran, 210 °C for raw soybean meal, and 200 °C for deoiled soybean meal. The products were also found to have antioxidant activity as tested by ABTS + scavenging assay. In addition, sensory evaluation of milk added with the hydrolysis product of deoiled rice bran indicated the potential use of the product as a nutritious drink.