Seasonal changes in the fatty acid profile of Kyrgyz khainak milk

Abstract

Khainak milk is a traditional source of nutrition for people living in the highlands of Kyrgyzstan. It is consumed both in its natural form and in the form of butter, cheese, and cottage cheese. We aimed to determine the composition of fatty acids in khainak milk, as well as its seasonal changes, since such data is lacking in literature. Fatty acids were determined by gas chromatography qualitatively and quantitatively in the milk from five lactating khainaks farm-bred in the Issyk-Kul region. The milk samples were collected and analyzed in the spring, summer, autumn, and winter seasons over three years (2019, 2020, and 2021). Kyrgyz khainak milk fat was mostly represented by saturated fatty acids, with a maximum content of 73.10 ± 2.19 g/100 g in winter. C14:0, C16:0, and C18:0 dominated in their composition, exceeding 5 g/100 g, with C16:0 (palmitic acid) reaching almost 35 g/100 g in winter. The flora of mountain pastures favorably contributed to monounsaturated fatty acids in khainak milk, especially oleic acid, whose content reached 26.85 ± 0.81 g/100 g in spring and then gradually declined to 18.90 ± 0.56 g/100 g, following changes in vegetation. Polyunsaturated fatty acids were found in small quantities varying from 3.25 ± 0.09 g/100 g in winter to 4.28 ± 0.12 g/100 g in summer. The seasonal changes in the fatty acid profile of Kyrgyz khainak milk are most likely due to differences in the animals’ diet. Our data can be used to optimize the process parameters for the production of full-fat products from khainak milk (cheese, butter, sour cream, etc.).

Keywords

• milk
• khainak
• season
• fatty acids
• saturated fatty acids
• monounsaturated fatty acids
• polyunsaturated fatty acids
• gas chromatography