| Oil-tea camellia seed oil, soybean oil, rapeseed oil and edible plant blend oil were heated for 2 h at different temperatures （100-200 ℃）, and the acid value, peroxide value, conjugated diene value, conjugated triene value and thiobarb acid-reactive substance(TBARS) value changes of the oils were determined to study the oxidative stability of the four edible oils at different temperatures. The results showed that the acid value, peroxide value, conjugated diene value, conjugated triene value and TBARS value of the four edible oils all increased with the increase of heating temperature, indicating that with the increase of heating temperature, the degree of oxidation of the four edible oils increased significantly. Compared with the unheated sample, the increase of each index of the four edible oils in descending order was as follows: for acid value, oil-tea camellia seed oil> rapeseed oil> edible plant blend oil> soybean oil; for peroxide value, edible plant blend oil> oil-tea camellia seed oil> rapeseed oil>soybean oil; for conjugated diene value, and conjugated triene value, rapeseed oil>soybean oil> edible plant blend oil>oil-tea camellia seed oil;for TBARS value, edible plant blend oil>rapeseed oil> soybean oil> oil-tea camellia seed oil. The synchronous fluorescence spectroscopy analysis showed that the phenolic fluorescence peak (360-390 nm) contained in the four edible oils at high temperature decreased or the peak shape became narrower, and the peak characterized oxidation products (413-520 nm) rose (except for edible plant blend oil), indicating that the components of the four edible oils changed during the oxidation. |
