Physicochemical and sensory characteristics of yoghurt produced from mixtures of cows' and goats' milk

Five formulations of yoghurt were prepared by mixing different proportions of non-homogenised cows' and goats' milk. Samples were analysed in terms of their pH, mechanical properties, flow behaviour, syneresis, colour and sensory properties throughout storage at 4 °C. The addition of goats' milk led to smaller changes in pH, a higher whiteness index, lower syneresis and a significant decrease in the firmness and consistence of the gel during storage. The physicochemical properties of yoghurts were correlated with gel microstructure. Sensory evaluation showed that incorporating goats' milk had a significant impact on the whiteness, flavour, syneresis and lumpiness of yoghurts. In general, the higher the goats' milk content, the greater the physicochemical and sensory differences with regard to the 100% cows' milk yoghurt. Samples with half and half cows'/goats' milk were preferred by the sensory panel.