Biogenesis of Conjugated Linoleic Acids

Abstract

One of the key areas in animal husbandry is to improve the quality (nutritional value) of dairy and meat products by enriching them with Conjugated Linoleic Acids (CLAs) like (cis-9, trans-11)- and (trans-10, cis-12)-octadecadienicacids; the former (rumenic acid) predominates all the CLAs. Though Vaccenic Acid (VA) is the immediate precursor of rumenic acid, dietary unsaturated fatty acids like Oleic Acid (OA), Linoleic Acid (LA) and a-Linolenic Acid (ALA) are the distant precursors of CLAs; and that CLA and VA are formed as intermediates during the biohydrogenation of the dietary OA, LA and ALA into fully saturated stearic acid. The mutual inter-relationship of rumen microbiota encompassing bacteria, protozoa and fungi facilitates the biohydrogenation process. Thus, this chapter critically evaluates the knowledge accumulated during the past four decades on the precursor of CLAs, micro-organisms involved in the production of CLA, the mechanism of biohydrogenation, and chemical synthesis of CLA, coupled with the rationale for biohydrogenation and factors affecting the production of CLA.