COMPOSITION OF KEFIR

The composition and flavor of kefir vary significantly, depending on a variety of factors including the source (cow, ewe, goat, mare) and the fat content (regular fat, lowfat, nonfat) of the milk used, the composition of the grains or starters, and the technological conditions of production.

The major products formed during fermentation are lactic acid, CO2, and alcohol. Many aromatic compounds, including diacetyl and acetaldehyde are present in kefir .
Diacetyl is produced by Str. lactis subsp. diacetylactis and Leuconostoc sp.
The pH of kefir is 4.2 to 4.6.
As in yogurt, the lactose content is reduced in kefir, and the b-galactosidase level is increased as a result of fermentation.
Information on vitamin and mineral content is limited and sometimes contradictory, but overall, there do not seem to be significant variations from that of the milk used. There is also a small increase in proteolysis, leading to an increase in free amino acids .