Combined enzyme-assisted aqueous extraction and supercritical CO₂ produces Rice bran oil with enhanced bioactive...

Rice bran (RB), a by-product of rice milling, is rich in bioactive compounds like γ-oryzanol and vitamin E. This study aimed to optimize enzyme-assisted aqueous extraction (EAAE) of rice bran oil (RBO) by employing response surface methodology to produce RBO using a combination of EAAE and supercritical CO₂ (EAAE+SC-CO₂) and compared the results with hexane extraction (HE). Optimized EAAE conditions (4:1 alcalase to pentopan, pH 7, 40 °C) indicated enhanced antioxidant activity and oil quality. Although HE gave the highest yield (9.03 %), EAAE+SC-CO₂ retained higher levels of γ-oryzanol (26.30 mg/g oil) and α-tocopherol (13.50 mg/g oil), and showed superior antioxidant activities (DPPH 6.53 mg TE/g oil; ABTS 14.37 mg TE/g oil; FRAP 2.98 mg TE/g oil; EC₅₀ 4.60 mg/mL), saturated fatty acid (19.30 %), and oxidative stability. These findings suggested that EAAE+SC-CO₂ is a promising green alternative to HE for producing high-quality, antioxidant-rich RBO.