Graininess and roughness of stirred yoghurt made with goat’s, cow’s or a mixture of goat’s and cow’s milk

The aim of this work was to study how the type of milk and the storage time affect the physicochemical characteristics, including graininess and roughness, of stirred yoghurt. Stirred yoghurt was produced from goat’s, cow’s or a mixture of goat’s and cow’s milk and was stored for 15 days at 4 ◦C. Yoghurt produced from goat’s milk was characterized by its lower number of grains, mean perimeter of grains, roughness, viscosity and water holding capacity in comparison to that of the yoghurt developed using cow’s milk. Yoghurt with half and half cow’s/goat’s milk had a higher viscosity and water holding capacity than that only containing goat’s milk and also had a lower number of grains, mean perimeter of grains and roughness than that only containing cow’s milk.