Effect of Milk Type and Storage Period on Physiochemical Characteristics of Yoghurt

Abstract

Milk and milk-products are important source of nutrients supply for mankind since immemorial time. In Sudan both cow’s and camel’s milk and their products are highly important in food security and nourishing people. This study was conducted at the department of animal production, Faculty of Agriculture, University of Sinnar as factorial experiments in completely randomized design (CRD) to investigate the effect of milk type (cows, camels milk and their mixtures) used for manufacturing yoghurt and the influence of storage time on physiochemical characteristics of yoghurt. Raw cows and camels milk were analyzed for nutrient contents and five types of yoghurt (Pure cow's milk yoghurt (A), pure Camel's milk yoghurt (B), yoghurt made of mixtures with a proportions of 1:1 (C), 1:2 (D) and 2:1 (E) Cow's to Camel's milk respectively) were made. Processing steps included milk heat treatment, incubation, cooling, and storage. All experimental yoghurt samples were analyzed at day one, seven and fifteen days. The Physiochemical properties of investigated yoghurt samples were significantly (P<0.05) lower in sample B during storage periods for titratable acidity with no differences between other samples. While the values were significantly (P<0.05) higher for total solids, fat content, solids not fat and protein for sample A in all storage periods compared to other tested samples. The study recommended that, milk mixtures with proportions of 1:1, 1:2 cow’s to camel’s milk respectively, could be used in commercial yoghurt production with reasonable nutritive value and consumer acceptance of the product.