A Review on Biohydrogenation and Effects of Tannin on It

The process called biohydrogenation occurs mainly in ruminant animals and during it, unsaturated fatty acids, and particularly poly-unsaturated ones (linoleic and linolenic) coverts to a saturated form of stearic acid. For many years, the beneficial effects of biohydrogenation intermediate fatty acids like cis-9 trans-11 linoleic acid, the main natural isomer of conjugated linoleic acids (CLA), and the isomer of trans-9 trans-11 CLA, especially in preventing cancer, has been proved. Many researches tried to use different components to interference biohydrogenation and increase the mediator substrates of CLA (e.g. vaccenic acid (VA)). Recently, due to the effects on rumen microorganism population, so do on biohydrogenation, tannin, a poly phenolic compound, is in the center of considerations. It is well known that tannins, specially condensed tannins, affect the bacteria population involved in biohydrogenation. Consequently, reduction in biohydro-genation via dietary inclusion of tannin is a useful tool to change the milk fatty acid profile toward health promoting fatty acids.