Effect of fruit nectar on physicochemical and sensory characteristic of goat\'s milk

Goat's milk yogurt has a high nutritional value and digestibility and less allergenicity than cow's milk products. The problem with goat's milk yogurt is the specific taste that results from the high concentrations of volatile fatty acids that cause goat's taste and limit consumers acceptance of this product. In this research, the effects of adding 20% pineapple and peach nectar on physicochemical (dry matter, fat, protein, acidity, synersis, water holding capacity and viscosity) and sensory properties of goat's milk yogurt during 28 days of refrigerated storage were evaluated. The results showed that adding nectar significantly reduced the amount of dry matter (p <0.05). In nectar-containing samples, dry matter content had increasing trend during storage. Fat and protein levels were significantly lower than control samples (p <0.05). The pH of nectar containing yogurts during storage was significantly lower and its acidity was significantly higher than that of control yogurt (p <0.05). The trend of synersis changes in nectar-containing yogurt samples was rising in the first week and then decreased until the end of the storage period and the process of changes in water storage capacity was initially decreasing and then increasing. The viscosity increased during the first week and then decreased significantly until the end of the storage period (p <0.05). The viscosity of nectar-containing yogurt samples was significantly lower than that of control sample (p <0.05). Sensory evaluation results showed that the highest overall acceptance score was given to the sample containing pineapple nectar (4.66, 4.46) and the lowest overall acceptance score to the sample containing peach nectar (3.36, 3.33) due to its dark color and sour taste on the 1st and 14th days respectively . Based on the experiments, the use of pineapple nectar is a good method in order to cover goat taste in goat's milk yogurt with preserved its qualitative characteristics.