Effects of microwave treatment on vegetable oil quality & biological activities

Background

The traditional roasting method has some disadvantages such as uneven heat transfer and long heating time, which will affect the quality and stability of oil. However, microwave (Mw) pretreatment has the characteristics of short processing time and low energy consumption, and there were many studied on Mw in the processing of vegetable oil.

Scope and approach

This review discusses the effects of Mw pretreatment on the various vegetable oils, including oil yield, physicochemical properties, minor lipid components and so on. The aim is to provide better support for the application of Mw in the vegetable oil industry, to align with contemporary processing principles of accuracy, moderation and health.

Key findings and conclusions

Mw enhances the extraction yield of oil, also effects on quality and biological activities of vegetable oils. An appropriate Mw pretreatment is beneficial for the production of minor lipid components, such as tocopherols, phenols, phytosterols, flavonoids, carotenoids; but no significant effect on the fatty acid compositions of oil. Correspondingly, oils exhibit good biological activity (such as antioxidant, anti-inflammation activity and oxidative stability) after Mw, which is mainly due to the increased formation of Maillard reaction products and dissolution of bioactive components. Furthermore, Mw heating can occur a series of reactions, which produces many aroma-active volatiles and improves the desired sensory characteristic.