Palm oil is extracted from the palm fruit (Elaeis Guineensis) of the oil palm tree. The oil squeezed from pulp is called palm oil, and the oil squeezed from nuts is called palm kernel oil. The composition of these two oils is quite different. Palm oil mainly contains palmitic acid (C 16) and oleic acid (C 18), and its saturation is about 50%. Palm kernel oil mainly contains lauric acid (C 12), and its saturation is above 80%. Traditionally, palm oil only refers to crude palm oil (CPO) and refined palm oil (RPO) squeezed from palm pulp, excluding palm kernel oil. It has been used as natural food for more than five thousand years. What is palm oil? It is an oil extracted from palm pulp, in which saturated fatty acids and monounsaturated fatty acids account for about half. But it is different from palm kernel oil and coconut oil, and its saturation is 35% lower than the latter. Coconut oil is almost the natural oil with the highest saturated fatty acid content, so it is "hard" than butter. When the temperature is warm, palm oil can still remain basically liquid. It is rich in carotene and tocotrienols (a natural vitamin E with higher biological activity than synthetic vitamin E), and its nutritional value is higher than that of animal fat. Palm oil also has a good feature, that is, it can be processed in grades. That is to say, palm oil can be divided into several products with different melting points through some subsequent physical treatments after oil pressing. Some of these products are concentrated in saturated fatty acids in palm oil, which are semi-solid or even solid at room temperature; Some products also contain more unsaturated fatty acids, which are liquid at room temperature. Those liquid palm oil components containing more monounsaturated fatty acids and vitamin E are often added to various blended oils to balance the proportion of fatty acids. Among them, those products that are semi-solid and solid at room temperature, similar to lard, butter and butter, are also used to replace animal fat and hydrogenated vegetable oil to make various snacks, biscuits and fried foods. The problem is that the healthy components such as carotene, vitamin E and monounsaturated fatty acids of this oil have been basically lost. In fact, it has little advantage compared with lard and butter. Japanese people pay great attention to the health of oils and fats, and have always disapproved of using this kind of palm oil in large quantities in food. In China, palm oil and hydrogenated vegetable oil are used in large quantities at the same time, which is likely to flood. Japanese people have good reason to worry, because palm oil is rich in palmitic acid with 16 carbon, and palmitic acid has a strong effect of raising blood lipid. Whether large intake will increase the risk of heart disease is still a worrying problem. In recent years, some animal studies and human studies have confirmed that pure palm oil has a good effect on controlling blood lipids, which is equivalent to olive oil in reducing "bad cholesterol" (LDL) and increasing "good cholesterol" (HDL). This gives people some peace of mind. Even so, whether to eat more palm oil is still controversial in academic circles, because those semi-solid palm oils, unlike pure palm oil, are probably bad for the heart. In addition, be careful that products that say "palm oil" actually use hydrogenated palm oil. Because palm oil, like soybean oil and rapeseed oil, will be hydrogenated, become hard and produce some trans fatty acids. Hydrogenated palm oil is also popular. It may be hidden in ice cream, or it may replace cocoa butter in chocolate containing cocoa butter substitutes, which plays an important role in satisfying the taste.