Production and properties of yoghurt made using mixture of cows and goats milk

Abstract

The effect of adding goat milk as cow milk substitute in the base formula of yoghurt on the acceptability and different properties of the resultant product was investigated. Set traditional yoghurt samples were made using fresh raw goat (G) and cow milk (C), and milk treatments obtained from three mixtures of goat milk added to the cow milk in gradual mixing ratios, named T1 (25% G + 75% C), T2 (50% G + 50% C) and T3 (75% G + 25% C) as given by experimental design respectively. The yoghurt treatments were analyzed in fresh, 7 and 14 days of cold storage (5±1°C). The obtained findings reveal that the added ratio of goat milk to the blend of yoghurt had a non-significant influence on total solids and protein contents and caused a gradual increase in the ash and fat. On the other hand, lactose, acidity, serum separation values and viability of lactic acid starter in resultant products were decreased. Using goat milk as a cow milk substitute for up to 50% of cow milk yoghurt preparation had a non-significant effect on the acceptability of yoghurt. The differences in the sensory properties were observed by using goat milk as a cow milk substitute higher than 50% of cow milk. It can be concluded that yoghurt products can be made by adding goat milk as a cow milk substitute for up to 50% without significant changes in physicochemical, microbiological and organoleptic properties.