Comparative analysis of conjugated linoleic acid content in cow, sheep and goat milk

Abstract

In recent years there has been increased interest in research on conjugated linoleic acid (CLA) and its potential health benefits: anticarcinogenic, antiatherogenic, antidiabetic and immunomodulatory effects. Term CLA describes a group of positional and geometric isomers of linoleic acid characterized by conjugated system of double bonds, separated by one single bond. The objective of this study was to analyze the differences in fatty acid (FA) profiles in cow, sheep and goat milk with an emphasis on the content of CLA. Milk samples were collected at conventional cow, sheep and goat farms, and according milk type were grouped in three groups. FA profiles were analyzed by gas chromatography. FAs were analyzed as methyl esters (FAMEs), and identified by comparison with methyl esters of standards. According to obtained results, significant difference (p<0.05) in CLA content was noted between three groups of samples, and also considerable individual variations in CLA content were noted inside each of group. Sheep milk samples were richer in CLA compared to goat and cow’s milk samples. Milk fat is the richest natural dietary source of CLA, and its content can be increased by manipulation of feeding regimes and genetic selection of dairy animals.