Some Properties of Probiotic Yoghurt Produced for Babies by Adding Fruit Puree, Containing B. infantis, B. bifidum, B. longum, L. paracasei

Probiotic yoghurt with fruit was produced to enrich the intestinal flora of infants and to prevent various ailments in infants when the flora is inadequate. Peach, apple and pear purees (10% and 20% each), cow milk, milk powder, starter culture (combination of Streptococcus thermophilus, Lactobacillus delbrueckii ssp. bulgaricus, Bifidobacterium infantis, Bifidobacterium bifidum, Bifidobacterium longum and Lactobacillus paracasei) were used in the production of probiotic yogurt for babies. Some properties of yoghurt samples were investigated during fermentation and on the 1st, 7th, 14th and 21st days of storage. After ten hours of fermentation, the lowest pH was observed in samples with apple puree. It has been determined that syneresis increases with increasing concentrations of fruit purees. The water holding capacity was less in yoghurts containing fruit puree compared to control yoghurt and in 20% fruit puree compared to yoghurts containing 10% fruit puree. The number of L. bulgaricus generally increased in all samples during storage. It was determined that the number of S. thermophilus in control sample was higher than other samples during storage. The number of L. paracasei and Bifidobacterium spp. decreased during storage. While the control sample remained probiotic until the 14th day of storage, other samples lost its probiotic properties before the 7th day of storage. Considering that the number of probiotic microorganisms in a probiotic product should be at least 106-107 CFU/g according to FAO, it has been decided that the most suitable fruits for probiotic yogurt with fruit puree are peach and apple, respectively. Considering the structural features, it is more appropriate to use 10% fruit puree, and considering the probiotic feature, it is more appropriate to use 20% fruit puree. Choosing the appropriate packaging and fixing suitable storage conditions will help probiotic microorganisms to preserve their vitality for a long time.