Rice Bran Polysaccharides: Structure, Modification, Bioactivity, and Application Potential in Food and Health Systems

Rice bran polysaccharides (RBPs) are natural plant-derived polysaccharides predominantly found in the rice bran layer, a major byproduct of rice milling, and exhibit a wide range of biological activities. These bioactive components, with their complex structures and diverse functions, hold immense potential for application in the food, pharmaceutical, and cosmetic industries. This review summarizes recent advances in the composition and bioactive functions of RBPs, with particular emphasis on how extraction methods and physicochemical modifications alter their molecular weight, monosaccharide composition, and chain conformation, thereby modulating key biological activities, including anti-inflammatory, antioxidant, immunomodulatory, and gut microbiota-regulating effects. Furthermore, to better elucidate their potential in industrial applications, this study systematically analyzes how the physicochemical properties of rice bran polysaccharides influence production and processing, with particular attention to their emerging roles as delivery carriers, food additives, and bioactive components.