Oils can be converted into solid fats by the process of hydrogenation. Hydrogenation: The vegetable oils containing glycerides of unsaturated fatty acids, undergo catalytic hydrogenation with hydrogen in presence of finely divided nickel. This results in conversion of a liquid glyceride (ie, an oil) into solid glyceride (ie, a fat) olein(anoil)∣CH2OCOC17H33CHOCOC17H33CH2OCOC17H33∣+3H2Nistearin(afat)∣CH2OCOC17H35CHOCOC17H35CH2OCOC17H35∣