Hydrogenation is a chemical process in which hydrogen atoms are added to unsaturated compounds, particularly fatty acids, in the presence of a catalyst such as nickel, under controlled temperature and pressure. In food chemistry, it is primarily applied to vegetable oils containing unsaturated fatty acids with one or more double bonds. The addition of hydrogen reduces these double bonds, converting liquid oils into semi-solid or solid fats, thereby increasing stability and shelf life by reducing susceptibility to oxidative rancidity. Partial hydrogenation leads to the formation of trans fatty acids due to isomerization of cis double bonds into