The potential anticarcinogenic conjugated linoleic acid, cis-9,trans-11 C18 : 2, in milk of different species: Cow, goat, ewe, sow, mare, woman

The distribution of the potential anticarcinogenic fatty acid cis-9,trans-1 1-octadecadienoic acid (rumenic acid) and other trans and cis fatty acids i n milk fat of different ruminants and non-ruminants including human milk wa s determined by gas-liquid chromatography. The CLA isomer cis-9,trans-11 wa s the predominant found. Its variation in milk fat of the bulk and individu al samples was substantial (0.07 - 1.35 % of FAME). Because feed compositio n and rumen microflora influence isomerisation of linoleic acid in the rume n, factors such as farm management and season were taken into consideration . CLA in milk of all ruminants was season-dependent and there exists a clos e positive correlation to trans vaccenic acid. Ewe milk is rich in CLA(1.1 %). Among non-ruminants mare milk was nearly CLA-free (0.09 %). Human milk contained significantly more CLA (0.42 %, P < 0.01) in comparison wih the a nalyzed milk of the other monogastrides. There are differences between milk - and non-milk drinkers. The arrangement of the species according to the in creasing CLA concentration in milk is: mare, sow, woman, great, cow, ewe. T he higher CLA content of ruminant milk compared with non-ruminant species i s inversely correlated to the content of PUFA and partly to MUFA (C) 1999 E lsevier Science Inc.