Impact of Time and Enzyme Concentration on Sangyod Rice Bran Hydrolysate: Phytochemicals, Antioxidants, Amino Acids, and Cytotoxicity

Abstract

This study investigated the production of Sangyod rice bran hydrolysate (SYRB) from Sangyod rice, focusing on incubation times (1, 3, and 5 h) and alcalase enzyme concentrations (0, 0.7, and 1% v/v). The results demonstrated a concentration-dependent relationship: higher alcalase concentrations increased hydrolysate yield. Prolonged incubation, especially with alcalase, enhanced substrate breakdown, further increasing hydrolysate production. The degree of hydrolysis, reflecting peptide bond cleavage, depended on both incubation time and enzyme concentration, emphasizing the role of enzyme activity in efficiency. Moreover, color analysis (L*, a*, b*) and color difference (∆E) revealed intricate changes from enzymatic hydrolysis. Proximate composition analysis showed higher protein and lipid content with increased enzyme concentration and longer incubation times, whereas ash content varied with both factors. Hydrolysate powders exhibited higher moisture content than raw rice bran, indicating the impact of the hydrolysis process. The study also explored SYRB's antioxidant properties and cytotoxicity, which were sensitive to incubation time and alcalase concentration. Longer incubation increased DPPH scavenging activity, with the highest efficacy at 3 h. Meanwhile, ABTS scavenging displayed a delicate balance with alcalase concentration. The cytotoxicity study of SYRB revealed that all concentrations of SYRB were non-toxic to C2C12 cells, with cell viability values exceeding 70%.