A comparative study of the physiochemical and compositional properties of Edilbay sheep milk

Sheep milk is emerging as a valuable alternative to cow milk, and to use sheep milk in the dairy industry, it is important to know its chemical composition and nutritional value. The physicochemical attributes and chemical composition of milk from a prominent sheep breed, Edilbay (Edilbayevskaya), were collected from farms in the Kazakhstani Almaty (AR) and Turkestan (TR) regions and compared with the available reference data. For the first time experimentally, the values of water activity a_w, 0.952 (for AR) and 0.967 (for TR), and moisture binding energy E, 4.423 kJ/kg (for AR) and 4.395 kJ/kg (for TR), of sheep milk are reported. All known essential amino acids were accessible in sheep milk of AR and TR. Five fatty acids (C10:0, C14:0, C16:0, C18:0, and C18:1) comprised a total of 73.5% and 73.2% of the fatty acids in AR and TR sheep milk, respectively. The content of saturated and unsaturated fatty acids, including the ratios of linoleic acid/linolenic acid (ω-6/ω-3) and linoleic acid/oleic acid (ω-6/ω-9), in sheep milk samples are comparable to known literature values. Electropherogram analysis showed the presence of all four fractions of casein: αS1-, αS2-, β- and κ-caseins, as well as α-lactalbumin and β-lactoglobulin. The concentration of κ-caseins in sheep milk of AR and TR were found to be 8.5%-9.2% and 7.1%-8.2% of total protein, respectively, and thus Edilbay milk can be considered as a valuable raw material. The study lays the foundation for the increasing export and adoption of ovine milk products to emerging dairy markets.