Microwave pretreatment on microstructure, characteristic compounds and oxidative stability of Camellia seeds

Camellia is an important woody oil crop and a primary source of edible vegetable oil. To optimize the extraction process of camellia (Camellia oleifera Abel.) seed oil, the similar impacts of microwave (MV) pretreatment (640 W, 0-8 min) on microstructure of camellia seeds (i.e. colour, oxidation-stability changes, tocopherol contents, sterol, squalene compounds, and fatty acid (FA) compositions were investigated. Generally, total carotene and sterol and squalene compounds of camellia oil were higher in microwave pretreated seeds than which in raw seeds (control). Seed samples were heated with the microwave (7%-8%) for 5 min, to demonstrated the excellent oxidative stability during accelerated oxidation. Tocopherol composition of the oil reached the maximum at different microwave treatment times, according to different moisture contents of camellia seeds. The fatty acid composition of microwave-pretreated camellia seeds variated insignificantly (p > 0.05). In conclusion, microwave pretreatment could improve the content of characteristic chemical composition and oxidative stability of camellia oil, while the moisture content and microwave time of camellia seeds needed to be controlled before oil extraction.

Automated summary

The study demonstrates that microwave pretreatment could enhance the content of characteristic chemical composition and oxidative stability of camellia oil, with insignificant variation in fatty acid composition of microwave-pretreated camellia seeds. Control of moisture content and microwave time of camellia seeds are crucial before oil extraction.