However, like margarine and shortening, (liquid) ghee contains a large amount of trans fatty acids, which are potentially very harmful to people, prone to obesity, memory loss and other negative consequences, and more food is even very easy to many kinds of disease risk. The basic principle of hydrogenation of fats and oils is to add a metal catalyst (nickel system, copper-chromium system, etc.) when heating vegetable oils containing more unsaturated fatty acids, pass hydrogen, so that the double bond in the unsaturated fatty acid molecule combines with hydrogen atoms to become a lower degree of unsaturation of fatty acids, and as a result, the melting point of the fats and oils increases (hardness increases).
Because hydrogen is added in the above reaction and the oil is "hardened", the oil obtained through this treatment is different from the original properties and is called "hydrogenated oil" or "hardened oil". "
The process is also called "hydrogenation".
In the beginning, ghee meant lard. Later the consumption of ghee made from hydrogenated vegetable oils or a few other animal and vegetable fats greatly exceeded that of lard. Depending on the source of the oil it can be classified as animal or vegetable ghee; partially hydrogenated or fully hydrogenated shortening; emulsified or non-emulsified ghee. On the basis of use and functionality it can be categorized as shortening for bakery, pastry, frosting and frying.