Lipolysis

What do we mean by lipolysis? Hydrolysis of ester bonds in lipids is called lipolysis. This may occur by enzyme action or by heat and moisture, resulting in the liberation of free fatty acids. Free fatty acids are virtually absent in the fat of living animal tissue. These can be formed, however, by enzyme action after  the animal is killed. Since animal fats are not usually refined, prompt rendering is of particular  importance. The temperatures commonly used in the rendering process are capable of inactivating the enzymes responsible for hydrolysis. In contrast to animal fats, oils  in mature oil seeds may have undergone a substantial hydrolysis by the time they have  harvested, giving rise to significant amounts of free fatty acids. Neutralization with alkali is thus required for most vegetable oils after they are extracted.