Non-Thermal Stabilization Strategies for Rice Bran: Mechanistic Insights, Technological Advances, and Implications...

Rice bran, a major byproduct of rice processing, is rich in unsaturated fatty acids, high-quality proteins, and bioactive compounds such as γ-oryzanol and ferulic acid. However, its poor storage stability and susceptibility to hydrolytic and oxidative rancidity critically limit industrial exploitation. Recent advances in non-thermal stabilization technologies-valued for their energy efficiency, scalability, and nutrient preservation-offer promising solutions. This review systematically elucidates the enzymatic and microbial mechanisms driving bran rancidity, emphasizing lipase and lipoxygenase activity, and critically evaluates the efficacy of emerging non-thermal strategies. Key findings highlight the superiority of non-thermal methods: cold plasma reduces lipase activity by 70% within 5 min via reactive oxygen species-induced structural disruption; ultra-high pressure preserves 95% of γ-oryzanol by selectively breaking hydrogen bonds in enzymes; high-energy electron beam irradiation suppresses rancidity markers by 45-78%; and enzymatic stabilization with immobilized papain achieves 78% lipase inactivation while retaining <5% nutrient loss. Compared to thermal approaches, non-thermal technologies enhance bioactive retention, while extending shelf-life by 2-3 weeks. By addressing challenges such as microbial synergy, parameter optimization, and industrial scalability, this review provides actionable insights for deploying green, energy-efficient strategies to valorize rice bran into functional foods and nutraceuticals, aligning with global demands for sustainable ingredient innovation.