Enzymatic fat hydrolysis and synthesis

Abstract

The hydrolysis of tallow, coconut oil and olive oil, by lipase from Candida rugosa, was studied. The reaction approximates a firstorder kinetics model. Its rate is unaffected by temperature in the range of 26-46 C. Olive oil is more rapidly hydrolyzed compared to tallow and coconut oil. Hydrolysis is adversely affected by hydrocarbon solvents and a nonionic surfactant. Since amounts of fatty acids produced are almost directly proportional to the logarithms of reaction time and enzyme concentration, this relationship provides a simple means of determining these parameters for a desired extent of hydrolysis. All three substrates can be hydrolyzed, almost quantitatively, within 72 hr. Lipase from Aspergillus niger performs similarly. The lipase from Rhizopus arrhizus gives a slow hydrolysis rate because of its specificity for the acyl groups attached to the α-hydroxyl groups of glycerol. Esterification of glycerol with fatty acid was studied with the lipase from C. rugosa and A. niger. All expected five glycerides are formed at an early stage of the reaction. Removal of water and use of excess fatty acid reverse the reaction towards esterification. However, esterification beyond a 70% triglyceride content is slow. © 1984 American Oil Chemists' Society.