关键词: 预处理技术, 冷榨双低菜籽油, 植物甾醇, 生育酚, 总酚

Abstract: The effects of microwaving and roasting pretreatments on the contents of phytosterols, tocopherols and total phenolics in cold pressed canola oil were studied. The rusults indicated that five phytosterols including cholesterol, brassicasterol, campesterol, β-sitosterol and stigmasterol were detected in both treatment groups. The amounts of individual and total phytosterols showed an overall upward trend with increasing microwaving time and the highest total amount of 982.12 mg/100 g was obtained at 2 minutes, which was 59.85 mg/100 g higher than that of the control group. Roasting pretreatment significantly affected the total phytosterol content of canola oil. The lowest and highest values were found in the samples roasted at 180 ℃ for 5 and 10 min, respectivley. Either treated oil mainly contained α-tocopherol and γ-tocopherol and had significantly higher contents of individual and total tocopherols than did the control. The content of total phenolics continuously increased with prolonging microwaving or roasting time, and it increased faster from 0 to 1.5 min than from 1.5 to 2 min of microwaving, and faster from 0 to 10 min than from 10 to 15 min of roasting at 180 ℃.

Key words: pretreatments, cold pressed canola oil, phytosterols, tocopherols, total phenolics