油脂对油炸食品中反式脂肪酸含量的影响

Effect of Different Oils on Trans Fatty Acid Contents in Deep-Fried Foods

目的:研究花生油、大豆油、菜籽油、24°棕榈油以及42°棕榈油5种油脂连续油炸薯条、油条和鸡块后,对油炸食品中反式脂肪酸含量的影响,从而为油炸食品工艺的选择提供实验依据。方法:采用5种油脂连续油炸薯条(176℃、2 min、45 s)、油条(176℃、2 min、30 s)和鸡块(176℃,3 min)5 d,并采用气相色谱法分析不同油脂对油炸食品中反式脂肪酸含量的影响。结果:使用不同种类油脂油炸的薯条、油条和鸡块均产生反式脂肪酸,其中,菜籽油煎炸的薯条和油条中反式脂肪酸最多,为38.74 mg/100 g和37.51 mg/100 g,棕榈油煎炸的油炸食品中反式脂肪酸含量最少,薯条为4.98 mg/100 g、油条为6.01 mg/100 g、鸡块为4.36 mg/100 g。结论:为使食品加工所产生的反式脂肪酸最少,应选用稳定性较好的42°棕榈油。

Purpose:In this study,we examined the effects of peanut oil,soybean oil,rapeseed oil,24°palm oil and 42°palm oil on the content of trans fatty acids(TFAs)in deep-fried foods after repeated cycles of continuous frying of French fries,Youtiao(deep-fried twisted dough sticks)and chicken nugget,aiming to provide an experimental basis for the selection of the optimal deep-frying process for foods.Methods:Each oil was used to sequentially process French fries(at 176℃ for 2 min and 45 s),Youtiao(at 176℃ for 2 min and 30 s)and chicken nugget(at 176℃ for 3 min)daily for 5 consecutive days.The fatty acid composition of the three fried foods was investigated using gas chromatography with flame ionization detection(GC-FID).Results:Trans fatty acids were produced during the deep frying of all types of foods with each oil.Fried fries and Youtiao deep-fried in rapeseed oil had the highest contents of TFAs of 38.74 mg/100 g and 37.51 mg/100 g,respectively.All foods deep-fried in palm oil had the lowest content of TFAs,which was 4.98,6.01 and 4.36 mg/100 g in French fries,Youtiao and chicken nuggets,respectively.Conclusion:In order to reach the lowest content of TFAs in deepfried foods,42°palm oil,with better stability,should be used.