Rice Bran Stabilization: Methods and Nutritional Impacts on Rice Bran Oil and Protein

Abstract

Rice bran is a nutrient-dense by-product of rice milling, rich in proteins, lipids, fiber, and bioactive compounds including tocopherols, tocotrienols, and γ-oryzanol. However, lipase rapidly hydrolyzes rice bran lipids, resulting in rapid free fatty acid accumulation, leading to deterioration of quality during storage. Hence, immediate enzyme inactivation after milling is crucial to suppress lipid hydrolysis, preserve quality, and extend shelf life. This review provides a comprehensive analysis of conventional thermal, novel thermal and athermal methods for rice bran stabilization, focusing on their mechanisms, enzyme inactivation efficiency, processing requirements, scalability, and effects on rice bran oil and protein. Emerging methods including cold plasma, pulsed electric field and enzyme inhibitors show potential for reducing thermal damage and maintain the nutritional quality, however, their application to rice bran remains limited compared to the conventional methods. A comparasion between thermal and athermal methods and SWOT analysis is provided, emphasizing stabilization efficiency, nutritional quality, and scalable methods for balanced stabilization and maximal nutrient retention.