Fatty Acid Composition of Goat and Sheep Milk: Transformation during Yogurt Production

Abstract

Introduction. Information on the structure of fatty acids is crucial for production and promotion of goat and sheep milk in dairy industry. The profile of fatty acids of milk fat can affect the nutrition value and market value of dairy products. Study objects and methods. The present research featured fatty acid structure of goat and sheep milk and its transformation during yogurt production. The fatty acid structure was studied using gas chromatography. The milk was obtained from goats of the Zaanensky breed and sheep of the North Caucasian breed. Their ratio in the yogurt was 1:1. Results and discussion. The content of saturated fatty acids was 12% less in goat milk than in sheep milk. Olein, stearin, and palmitic acids are the main fatty acids in the fatty phase of milk and yogurt. The research revealed some changes in concentration of individual fatty acids during milk processing and during the storage of yogurt. As a result of ripening and storage, the amount of saturated fatty acids in yogurt increased by 5% on day 7, in comparison with the initial dairy mix. The content of the polynonsaturated fatty acids decreased by 19.27%. Goat milk had the highest value of the ratio of the hypocholesteremic and hypercholesteremic fatty acids. Goat milk demonstrated the most acceptable fatty acid structure in terms of healthy nutrition and prevention of atherosclerosis and thrombogenesis. During yogurt production and storage, the monononsaturated and polynonsaturated fatty acids decreased, while the content of saturated fatty acids increased. Thus, goat milk can increase the amount of monononsaturated and polynonsaturated fatty acids in dairy products. However, the research also revealed a general tendency to decrease in monononsaturated and polynonsaturated fatty acids during yogurt production and storage, with a parallel increase in the content of saturated fatty acids. Unlike ship milk, goat milk had a lower value of the indices of atherogenicity and thrombogenesis. Conclusion. The indices of atherogenicity and thrombogenesis provided additional information on the functional properties of the product. The established features of the fatty acid profile and its transformation during yogurt production provide data that can help produce qualitatively new dairy drinks with a healthy fatty acid profile.