ABSTRACT
To study the biological value of kumyss leaven, experiments were made with mono-cultures contained by kumyss leaven. The cultures Streptococcus lactis, strain 1-27, Lactobacillus bulgaricus, strain B-3, acetic acid bacteria and the yeast culture Torulopsis kefir var kumis, strain 17 contained by kumyss leaven were employed as test objects. Experiments were performed with defattened cow's milk. The following parameters were measured: acidity according to Turner (T degree), dry residue, total nitrogen according to Kjeldahl's micromethod, amino acid composition by ion-exchange chromatography, biological value according to the amino acid score. All the parameters were studied over time for 5 days. The vital activity of the cultures produced different effects on the acidity, dry residue and amino acid composition, therefore on the biological value of kumyss leavens. It is assumed that the data obtained may be of importance for kumyss manufacture.