ABSTRACT
I. INTRODUCTION The development of methods to improve the nutritional and functional properties of fats and oils is of great interest to food processors. The molecular weight, unsaturation, and positional distribution of fatty acid residues on the glycerol backbone of triacylglycerols are the principal factors determining the physical properties of fats and oils (1,2). Chemical interesterification produces a complete positional randomization of acyl groups in triacylglycerols. It is used in the manufacture of shortenings, margarines, and spreads to improve their textural properties, modify melting behavior, and enhance stability (3,4). Interest in interesterification from a nutritional and functional standpoint is increasing since it can be used to produce margarines with no trans unsaturated fatty acids, synthesize cocoa butter substitutes and improve the nutritional quality of some fats and oils (5). Recently, research efforts have been directed to substituting some chemical interesterification applications with enzymatic interesterification because of the inherent advantages associated with the enzymatic process. Enzymatic reactions are more specific, require less severe reaction conditions, and produce less waste. Also, when immobilized, enzymes can be reused, thereby making them economically attractive (6). Interesterification, whether chemical or enzymatic, is the exchange of acyl groups between an ester and an acid (acidolysis), an ester and an alcohol (alcoholysis), an ester and an ester (transesterification) (7).
