Recent Advances in the Preparation and Bioactive Properties of γ-Oryzanol

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.