Kefir Research Paper

Kefir Origins and Characteristics

Kefir is a viscous, slightly carbonated dairy beverage that contains small quantities of alcohol and, like yoghurt, is believed to have its origins in the Caucasian mountains. It is also manufactured under a variety of names including kephir, kiaphur, kefer, knapon, kepi and kippi (Koroleva 1988a). The FAO/WHO (2001) have proposed a definition of kefir based on the microbial composition of both kefir grains (the starter culture used to produce kefir) and the final kefir product (see Table 1).

The flavor, viscosity and microbial/chemical composition of the final kefir product can be affected by the size of the kefir grains added to the milk, the occurrence of turbulences during fermentation, the rate, temperature

Moreover, kefir grains generally contains more lactic acid bacteria (108-109) than yeasts (105-106) and acetic acid bacteria (105-106), although this composition might be affected by the process of fermentation. A further research by Garrote et al, studied functioning mechanism of kefir grains bacteria. It was revealed that L. kefir and L. parakefir had S-layer proteins which was responsible to their auto-aggregation and haemagglunation abilities. Besides, Caco-2-cells were also found in those heterofermentative bacteria, giving a hypothesis that they might be good

Kefir grains have high proteinase activities which increase the possibility of bioactive peptides presence thus kefir contains a large number of peptides.

Health Benefits of Kefir

Stimulation of the immune system

It has been proposed that stimulation of the immune system may be one mechanism whereby probiotic bacteria may exert many of their beneficial effects (De Simone et al. 1991; Gill 1998). However, peptides formed during the fermentation process or during digestion have also been shown to be bioactive, and demonstrate a variety of physiological activities, including stimulation of the immune system in animal models (LeBlanc et al, 2002; Matar et al. 2003)

Thoreux and Schmucker (2001) fed kefir produced from grains to young (6 months) and old (26 months) rats and found an enhanced mucosal immune response in the young animals, as shown by a higher anti-cholera toxin (CT) IgA response compared to controls.

Stimulation of the immune system may also occur due to the action of exopolysaccharides found in kefir grains. Furukawa et al. (1992) have also shown that a water-soluble fraction of kefir grains may act as a modulator of the immune