Evaluation of the Fermentation Profiles and Quality Attributes of Yogurts Made from Cow, Goat, and Mixed Milk.

The use of mixed cow-goat milk in yogurt production allows for balancing fermentation performance, textural properties and sensory attributes of the products. This study evaluated the fermentation behavior and physicochemical, microbiological, textural, and color properties of yogurts produced from cow milk (A), goat milk (E), and mixed cow-goat milk at volume ratios (v/v) of 75:25 (B), 50:50 (C), and 25:75 (D). Volatile organic compounds (VOCs) were analyzed in milk before fermentation and in yogurts after production and during two weeks of refrigerated storage. Sensory attributes were assessed after two weeks of storage. An increase in the proportion of goat milk in the milk blend shortened the fermentation time, whereas a higher proportion of cow milk enhanced the survival of lactic acid bacteria (LAB), improved water-holding capacity (WHC), strengthened textural properties, and reduced syneresis. Yogurts with higher proportions of goat milk exhibited increased lightness and whiteness. Milk type influenced chemical composition, with higher fat content and lower lactose content observed in goat milk yogurts. A higher proportion of goat milk in the milk blend promoted the formation of methyl ketones and aldehydes associated with a characteristic fatty aroma. Among the mixed-milk yogurts, the sample containing 25% goat milk (D) achieved the highest sensory acceptance. The study demonstrated that cow-goat mixed-milk yogurts represented a balanced compromise between textural stability, microbial viability, and sensory acceptance.