Polyunsaturated fatty acids microbial oils

Scott, T. W., Cook, L. J. and Mills, S. C. 1971. Protection of dietary polyunsaturated fatty acids against microbial hydrogenation in ruminants. J. Am. Oil Chem. Soc. 48, 358-364. 

In most natural fats the double bonds of unsaturated fatty acids occur in the cis configuration. In milk fat a considerable proportion is in the trans configuration. These trans bonds result from microbial action in the rumen where polyunsaturated fatty acids of the feed are partially hydrogenated. Catalytic hydrogenation of oils in the fat industry... 

C2o polyunsaturated fatty acids (PUFAs see Tables 6 and 7 and Fig. 4) exhibit unique biological activities, such as lowering the plasma cholesterol level and preventing thrombosis. As food sources rich in PUFAs are limited to a few seed oils and fish oils, alternative microbial sources of PUFAs are of high interest. The species distribution of PUFAs produced by Mor-... 

Production of TAG enriched with polyunsaturated fatty acids (PUFA) via lipase catalysis in codliver oil has also been described (Haraldsson et ah, 1989). Preparation of y-linolenic acid enriched TAG via rapeseed lipases (Syed Rahmatullah et aL, 1994 Jachmanian and Mukerjee, 1996) and microbial lipases (Akoh et aL, 1995, 1996) has also been reported. Incorporation of eicosapentaenoic and docosahexaenoic acids into peanut oil via transesterification catalysed by microbial lipases has been reported by Sridhar and Lakshminarayana (1992). According to Wada and Koizumi (1986) and Kimoto et aL (1994) interesterification of fish oils to form TAG containing PUFA in the 2-position rather than the 1,3-positions increases the oxidative stability of the modified oil as compared to its original counterpart. 

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