Chemical, Microbiological, and Functional Characterization of Kefir Produced from Cow’s Milk and Soy Milk

Table 4

Organic acids in unfermented and fermented cow’s milk and soy milk with kefir grains.

Organic acids (mg 100 mL^−1)	Unfermented cow’s milk	Fermented cow’s milk (cow’s milk kefir)	Unfermented soy milk	Fermented soy milk (soy milk kefir)
Lactic acid	2.0 ± 0.1	1,306.5 ± 111.9	4.1 ± 0.4	697.7 ± 15.6
Acetic acid	20.0 ± 1.4	135.3 ± 15.2	6.2 ± 0.7	51.8 ± 18.0
Pyruvic acid	ND	4.5 ± 7.8	ND	ND
Citric acid	149.0 ± 9.6	109.3 ± 26.6	217.3 ± 14.1	260.2 ± 22.9

ND: not detected. Seven consecutive fermentations were carried out; samples on days 1, 4, and 7 were taken; and organic acids were determined. The values shown are the mean ± standard deviation of these three measurements.