ABSTRACT
Structured triacylglycerols (ST) are generally any fats that are modified or restructured from natural oils and fats, or fatty acids therefrom, having special functionality or nutritional properties for edible or pharmaceutical purposes. This definition covers any fats produced by either chemical or enzymatic methods for special functionality or nutritional use, including cocoa butter equivalents, breast milkfat substitutes, some low-calorie fats, oils enriched in essential fatty acids [y-linolenic, arachidonic, a-linolenic, eicosapentaenoic (EPA), and docosahexaenoic (DHA) acids], margarines or other plastic fats, and structured triacylglycerols containing both long-chain (essential) and medium/short-chain fatty acids. This chapter focuses only on structured lipids that contain both long-chain polyunsaturated fatty acids (PUFA) and medium-chain fatty acids (MCFA) and are produced by chemical or enzymatic methods. Other types of ST are discussed in other chapters of this book. Therefore, the definition of ST in this chapter includes only those oils that contain fatty acids of different chain lengths, either randomly or specifically. Fatty acid length is normally described as long chain (> 12), medium chain (8-12), and short chain ( <8). ST are mainly produced for nutritional use. However, some of them also have special functionality as confectionery fats, frying fats, or coating fats.
