Dynamic evaluation of the nutritional composition of homemade koumiss from Inner Mongolia during the fermentation process

Abstract

Koumiss plays an important role in income generation for herdsmen and the daily nutritional intake of local people. In this study, the pH, protein, fat, lactose, lactic acid, amino acid, and vitamin content of koumiss were investigated during the entire fermentation period. The results showed that the protein content of fresh mares’ milk and koumiss ranged from 1.86 ± 0.07% to 2.22 ± 0.08%; fat content ranged from 0.74 ± 0.16% to 1.480 ± 0.08%; VB1 concentration ranged from 1.48 ± 0.12 to 4.86 ± 0.42 µg/100 g; VB2 concentration ranged from 2.48 ± 0.12 µg/100 g to 4.86 ± 0.32 µg/100 g; and VE concentration ranged from 99.90 ± 0.05 to 44.63 ± 0.63 µg/100 g. There were significant differences between fresh mares’ milk and koumiss in relation to VE content. The content of 17 amino acids ranged from 2.40 ± 0.11 µg/100 g (for MET) to 39.64 ± 0.01 µg/100 g (for GLU). Fresh mares’ milk and aged koumiss had high nutritional value; however, unripe koumiss (i.e., with a shorter fermentation time) had low nutritional value. Based on the data from this study, an optimized manufacture process for koumiss is proposed. Practical applications The dynamic changes of chemical and nutritional composition of koumiss were evaluated in this present paper. The nutrient content of koumiss is the highest at the point of 12 hr fermentation. The optimized manufacture process for koumiss is proposed based on the result of this study. This paper will provide the basic information for koumiss industrial application.