Effects of different fruits and storage periods on microbiological qualities of fruit-flavored yogurt produced in Turkey

Comparative microbiological analyses of fruit-flavored yogurt, plain yogurt, and plain yogurt with 8% sugar were conducted in this research. The fruit-flavored yogurts were produced from evaporated cow's milk (19.75% dry matter) containing 16% jam prepared with an equal weight of sugar and fruit (sour cherry, orange, strawberry, or banana). The total plate count, lactic acid and coliform bacteria, and yeast and mold counts were determined in yogurt samples stored for 1, 3, 5, 7, 9, and 13 days. In conclusion, it is suggested that these types of yogurt should not be stored longer than 7 days, because when a carryover culture is used for yogurt production, most likely yeast contamination will occur. Otherwise, pure starter culture should be utilized in yogurt production.