Generally, it is thought that animal oil is made of saturated fatty acid, and plant oil is made of unsaturated fatty acid. However, animalis food is not always made of only saturated fatty acid. A typical example of this is fish oil. Although the fat in fish is animalis, it contains much unsaturated fatty acid. Fish oil has a nature similar to plant oil because of this fact.
On the contrary, such plant oils as coconut oil, palm oil and cocoa butter are easily solidified.
In the case of saturated fatty oil, the less the number of carbon and the shorter the chains of fatty acid are, the more easily it become solidat normal temparature.
In the case of monounsaturated fatty acid and polysaturated fatty acid, which we daily have, the more double bonds are, the lower temparature they melt at. In other words, melting point becomes lower.
The fatty acid with four carbons has the shortest chains. This fatty acid is contained in the oil?of butter. This acid is called butyric acid. As the number of carbon increases, it become the fatty acid with eight to sixteen carbons, which is in coconut oil or palm acid, and becomes stearic acid?and so on with even more carbons. Saturated acids are stearic acid, palmitate acid, etc..
Linoleic acid and linolenic acid are well-known unsaturated fatty oil, but also eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are becoming to be famous.
linoleic acid has two unsaturated bonds, linolenic acid has three, EPA has five and DHA has as many as six unsaturated bonds.
It is said that polysaturated fatty acid with more than two double bonds is good for your health.
