Probiotic properties, sensory qualities, and storage stability of probiotic banana yogurts

The quality properties of probiotic yogurt samples made with banana marmalade (BM), which can be a probiotic product, were examined. Yogurt samples were produced from cow milk inoculated with yogurt cultures and probiotic cultures (Lactobacillus acidophilus, Bifidobacterium bifidum, and an equal mixture of the 2 strains), and then 15% BM was added to each yogurt sample. Acidity, pH, bacteria counts, and sensory analysis of the yogurt samples were investigated on days 1, 3, 5, 7, 10, and 14 during storage at 4 degrees C. Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus thermophilus, L. acidophilus, and B. bifidum counts generally decreased during the storage period. The highest L. acidophilus count (8.145 log cfu/g) was found in L. acidophilus + B. bifidum-mixed yogurt on the third day. The highest B. bifidum count (6.38 log cfu/g) was recorded in B. bifidum-fermented yogurt on the first day. Yeast and mold counts of all yogurts increased during the storage period. Coliform bacteria and Staphylococcus aureus were not found in the yogurt samples. The sensory quality and probiotic properties of all of the yogurts decreased aft er 7 days. The highest sensory score was observed in the control and the yogurts produced by adding B. bifidum.