Dual-site competitive mechanism of phytosterol ester oxidation and its implications for health risks and food design

Phytosterol esters (PE) are susceptible to oxidation during thermal processing and storage, leading to the formation of potentially harmful derivatives. This review systematically elucidated the dual oxidation sites competitive mechanism of phytosterol esters (PE) between the sterol nucleus and the fatty acid chain during thermal processing and storage. The dominant oxidation pathway was dynamically regulated by key factors such as temperature, oxygen, and the food matrix. Furthermore, phytosterol oxidation products (POPs) and fatty acid oxidation products (FAOPs) exhibited distinct differences in digestibility, bioactivity, and potential health risks, including cytotoxicity and pro-inflammatory effects. Therefore, the review proposed targeted antioxidant strategies tailored to different food systems and introduced novel approaches for the design of functional lipid products with enhanced oxidative stability. This work provided a theoretical foundation for optimizing both the functionality and safety of PE-fortified foods, supporting the development of healthier and more stable functional food products.