Comprehensive analysis of phenolic profile, their antioxidant activities, and physicochemical characteristics of rapeseed oil under various microwave and storage conditions

Rapeseed oil (RO) is a widely consumed edible oil in China, valued for its nutritional benefits and oxidative stability. Phenolic compounds in RO function as natural antioxidants, enhancing both its health-promoting properties and shelf life. In this study, a targeted metabolomics method was developed and validated for the quantification of 24 phenolic compounds. The method demonstrated high accuracy, with determination coefficients exceeding 0.99. Chemometric analysis revealed that microwave power exerted a greater impact on phenolic profile of RO than storage duration. Specifically, higher microwave powers and shorter storage periods associated with increased content of most phenolics. Sinapic acid emerged as a key marker distinguishing microwave-pretreated ROs. The most significant pathway associated with phenolics was flavone and flavonol biosynthesis. Changes in antioxidant capacity, color, oxidation indicators, and fatty acid composition of RO following various microwave and storage conditions were anatomized. Strong relationships were observed between phenolic profile and antioxidant activity, color, and oxidation indicators. These findings provide valuable insights into the nutritional evaluation and shelf-life prediction of RO, providing a foundation for optimizing processing and storage conditions to preserve its quality and functionality.