Tea seed oil from Camellia oleifera Abel seed were roasted by three different treatments which are high temperature treatment (180℃), medium temperature treatment (145℃) and low temperature treatment (75℃). After roasting, seeds were pressed and the oil were storaged at 30 ℃ for 0, 45, 90, 135, 180, 225 days to examine the changes of oil quality, antioxidant activity, physiological functional composition and fatty acid composition.
The results found the iodine value of fresh tea seed oil was 79 which was belong to the non-drying oil. All the oxidation experiment results (acid value, peroxide value, conjugated diene and p-anisidine value) showed a significantly upward trend as elongate the storage time and the low temperature treatment of tea seed oil rised fastest. At the same time, ΔE also rised with storage time increased, which was indicated the roasting temperature and storage times were significantly affect the quality and the color of oil. The highest content of fatty acid is the oleic acid, that was about 81%. Polyunsaturated fatty acid content showed a downward trend with storage times. High temperature treatment of tea seed oil has highest antioxidant activity. The scavenging DPPH radical ability and reducing power of high temperature treatment of tea seed oil were better than the other two oils. With the increasing of storage time, the antioxidant activity of all the samples were decreased and the two experiment parameters - roasting temperature and storage time did show significant differences. Total phenols compounds and flavonoids were decreased with storage times and the content of high roasting temperature treatment was significantly higher than the other two treatments. This trend was similar to antioxidant activity . The results also indicating the antioxidant activity of high roasting temperature of tea seed oil comes from the total phenols and flavonoids. Low roasting temperature treatment oil retained more chlorophyll and phytosterol. Chlorophyll content showed the same trend with a value, that means the chlorophyll content is related with green of tea seed oil.
