Abstract: γ-Oryzanol, one of the most abundant bioactive compounds in rice processing by-products, is primarily extracted from cereal-derived materials such as rice bran oil. This review systematically summarizes the advantages and limitations of conventional γ-oryzanol extraction methods (including solvent extraction, alkaline extraction followed by acid precipitation, solvent extraction assisted by microwave, ultrasound or ohmic heating, supercritical CO2 extraction, and subcritical extraction) and purification techniques (such as membrane separation, adsorption, chromatography, distillation, and crystallization). Recent improvements in γ-oryzano preparation methods have focused on optimizing green extraction technologies and separation technologies to enhance the extraction efficiency and product purity. As novel green extraction techniques, supercritical CO2 extraction and subcritical dimethyl ether extraction result in much improved yield of γ-oryzanol. As a state-of-the-art purification method, semi-preparative chromatography yields 99% pure γ-oryzanol. This compound exhibits multifaceted bioactivities, including hypolipidemic, antioxidant, and anti-inflammatory properties. Current research focuses on its antioxidant, anti-inflammatory, and neuroprotective/regulatory mechanisms; however, the neuro-metabolic-immune network multi-target synergistic mechanism is unclear yet. While γ-oryzanol is predominantly utilized as a food additive and dietary supplement, its pharmaceutical application remains largely confined to adjuvant therapy and it has been insufficiently applied in emerging fields such as anti-aging treatment and skin repair. In addition, γ-oryzanol shows potential in agriculture and emerging medical materials. In alignment with China’s national strategies for grain conservation and loss reduction, Healthy China, and high-quality development, this article calls for more research on the isolation of bioactive components from rice processing by-products.

Key words: sources and structure of γ-oryzanol; extraction; separation and purification; bioactive functions; application