| The fatty acid composition, contents of polyphenols, tocopherols, phytosterols, benzo(a) pyrene, aflatoxin B1, 3-MCPD ester, and oxidative stability (OSI) of seven kinds of edible vegetable oils were determined and analyzed. The results showed that the contents of unsaturated fatty acids of seven kinds of edible vegetable oils were all relatively high (78.29%-91.92%), but the fatty acid compositions were different among different oils. The oil-tea camellia seed oil, sunflower seed oil and rapeseed oil had the highest contents of monounsaturated fatty acid (80.44%), polyunsaturated fatty acid (61.18%) and unsaturated fatty acid (91.92%) respectively. The content of total polyphenols was the highest in rapeseed oil, reaching 139.83 mg/kg. The content of γ-tocopherol was relatively high in soybean oil, rapeseed oil and corn oil, and α-tocopherol was relatively high in sunflower seed oil and rice bran oil. Total tocopherols content was the highest in soybean oil (1 129.21 mg/kg). The main phytosterols composition was β-sitosterol and the contents of phytosterols were relatively high in rice bran oil (10 705.8 mg/kg) and corn oil (8 596.7 mg/kg). Benzo(a)pyrene and aflatoxin B1 were detected from few edible vegetable oils and the contents were all lower than the national standards. The total contents of 3-MCPD esters were low in rapeseed oil, sunflower seed oil, soybean oil and peanut oil (lower than 1.0 mg/kg). The oxidative stability index(OSI) results were higher for rapeseed oil and soybean oil and lower for sunflower seed oil and oil-tea camellia seed oil, which was extremely, significantly and positively related to the total polyphenols content. |
