ABSTRACT
Lipases (E. C. 3.1.1.3) are important hydrolytic enzymes that catalyze the hydrolysis of fats and oils. Unlike other enzymes, oil/water or air/water interfaces activate the lipase.1 In a natural environment, water acts as a secondary substrate for the hydrolysis of lipids. With the recent advancement in reaction medium engineering and enzyme technology, it is now possible to use lipases in synthetic applications. Introduction of a microaqueous environment with decreased and controlled water activity drives the hydrolytic reactions toward the synthetic side. The reversal of hydrolysis reaction is due to the change in the equilibrium constant in low water activity systems.2 Such a possibility opened a new branch of biotechnology for the synthesis of a variety of food, pharmaceutical, and chemically important compounds with greater specificity than chemical catalysis. There are many advantages of using enzymes for these purposes, including reactions at mild temperature, atmospheric pressure, low energy consumption, and cleaner products with minimum or no by-products. Lipases can be applied to regio-and stereospecific
synthesis of drugs in pharmaceutical industries, enantiometrically pure compounds synthesis in chemical industries, modification of fats and oils, and flavor esters synthesis in food industries.3,4
The diversity of fatty acid composition of natural lipids gives them a variety of physiochemical, nutritional, and functional properties. Fatty acid carbon chain length, one or more unsaturations, and distribution of fatty acids in a triacylglycerol molecule give each fat or oil its unique properties, and hence their application. Lipids are derived from both plant and animal sources; however, not all lipids are suitable for oral consumption, for instance, castor oil. The majority of the lipids from these sources are edible. Lipids are part of the human diet and essential for healthy living. A high concentration of lipids is found in neuronal tissues and cell membranes as insulators and barriers for compartmentalization of cellular organelles. Nutritionally, lipids are classified based on their importance as essential or nonessential with respect to their fatty acid composition. Essential fatty acids are those that cannot be synthesized by human biochemical machineries such as linoleic, linolenic, and arachidonic acids.
