The physical properties of oils and fats depend on their chemical properties, such as unsaturation, saturation, chain length, and distribution of the three hydroxyl groups of glycerol in the fatty acids. These characteristics change by hydrogenation, fractionation, blending, and interesterification (IE), hence improving the spectrum for the application of the oils and fats. IE is a process where the fatty acids have been moved from one triglyceride molecule to another and it does not alter the fatty acids. IE (chemical and enzymatic) is used to deal with the problems of plastic fat products such as granular development, texture breakdown, lumpy appearance, post hardening, consistency, melting point, and rancidity and create oil more suitable for deep frying or making margarine with good taste and low content of saturated fatty acids, etc. Nutritionally, IE contributes in eliminating or reducing trans fatty acids, providing a higher essential fatty acid activity. Trans and hydrogenated fats increase the coronary heart disease risk factors.