加热过程中植物油品质变化规律的研究

摘要

以7种植物油为研究对象,在一般烹饪温度180℃条件下加热,分别在0.5h、1h、2h、4h 和6h 取样,分析加热时间对植物油中酸价、过氧化值及脂肪酸的变化情况,研究其变化规律.结果表明7种植物油酸价随着加热时间的增加整体呈升高趋势,但增幅并不明显;过氧化值均呈现出先上升达到峰值后下降再上升的规律;饱和脂肪酸的含量在加热过程中菜籽油、玉米油、大豆油和亚麻籽油都呈现出规律的显著性增大,而葵花籽油和橄榄油以上下浮动的形式增大,花生油则保持不变;单不饱和脂肪酸除橄榄油出现上下波动增大外,其余6种植物油均呈现出规律的显著性增大;多不饱和脂肪酸在加热过程中均呈现出规律的显著性减小,即其含量与加热时间成正相关.此外反式脂肪酸的含量在加热过程中均呈现出规律的显著性增大.其中增幅最大的是菜籽油,最小的是橄榄油.%The changes of acid value,peroxide value and fatty acid composition for 7 kinds of plant oils heated at 180℃ for 0,0.5,1,2,4,6 hours were studied,respectively.The results showed that with the increasing of heating time,the acid values of all the 7 kinds of plant oils did not significantly go up,while the peroxide values increased and then decreased after the peak value,followed by a rising trend again. During the heating process,the SFA within the rapeseed oil,corn oil,soybean oil and flaxseed oil in-creased significantly,as a contrast,the increase of SFA in sunflower oil and olive oil was not significant. As for the peanut oil,the SFA content remained the same.The MUFA fluctuated in olive oil and increased significantly in other plant oils. The PUFA in the 7 plant oils all decreased significantly in the heating process,and the content was positively correlated with the heating time.In addition,the content of trans fatty acids in the heating process also showed a significant increase rule,and the largest increase appeared in the rapeseed oil while the smallest in the olive oil.