食用油有植物油和动物油两大类。但各种食用油的主要成分都是中性脂肪,其次为磷脂、胆固醇和维生素A、D、E等。脂肪由各种脂肪酸构成,它供给人体热量和不饱和脂肪酸。这种不饱和脂肪酸是人体不可缺少的物质,如果体内缺乏它,便会出现皮肤粗糙、脱屑及头发干脆易落等现象;反之,若供应充足,人体皮肤就光滑润泽,头发乌亮,容颜更加美丽。因此,人们又称不饱和脂肪酸为“美容酸”。可见,油的营养价值高低是 Edible oil vegetable oil and animal oil are two categories. However, the main components of all kinds of edible oil are neutral fat, followed by phospholipids, cholesterol and vitamins A, D, E and so on. Fat is made up of various fatty acids, which supply body calories and unsaturated fatty acids. This unsaturated fatty acids are indispensable to human body, if the body lacks it, there will be rough skin, scaling and hair easily fall easily phenomenon; the other hand, if the supply is adequate, the body smooth and moist skin, shiny black hair, the appearance of more beautiful. Therefore, people also called unsaturated fatty acids as “beauty acid.” Visible, the nutritional value of oil is high