Production of fruit-based probiotic fermented milk beverage

In this study, four different probiotic fermented milk beverages namely as control (K), probiotic fermented milk beverage with black mulberry (DFI), probiotic fermented milk beverage with grape (UFI) and probiotic fermented milk beverage with cornelian cherry (KFI) were produced. Milks used in production were inoculated with starter culture containing Streptococcus thermophilus, Lactobacillus bulgaricus, Lactobacillus acidophilus and Bifidobacterium lactis and incubated at 40℃. The fermented milk beverages were prepared by mixing the yoghurt with black mulberry, grape and cornelian cherry fruit juices. Microbiological analysis such as counts of S. thermophilus, L. bulgaricus, L. acidophilus and B. lactis, physico-chemical analysis such as pH, titratable acidity, syneresis, color (L, a, b); sensory properties such as texture, flavor, odor, color, aroma intensity, flavor and overall acceptability were determined on the 1., 7., 14., 21. and 28. days of storage; and also the average composition of final beverages including dry matter, brix, ash, ascorbic acid, total phenolic, total antioxidant capacity (DPPH) were investigated. The viable cell counts of S. thermophilus, L. bulgaricus, L. acidophilus and B. lactis were detected within the recommended bio-therapeutic level (>106 log cfu/mL) as a result of the potential prebiotic effect of components present in fruit-based probiotic fermented milk beverages (p<0,01). The variations in pH, titratable acidity, syneresis and color values of the drinks were determined statistically different (p<0,01). The differences of the color values were attributed to the natural coloring pigments of the fruits. The value of total antioxidant capacity in KFI samples found higher due to the high levels of ascorbic acid and total phenolic compounds. UFI samples had a more favored taste than the other beverages, eventhough the overall sensory acceptability of all beverages were found similar. We can conclude that the probiotic fermented milk drinks produced with black mulberry, grape and cornelian cherry were found to have high levels of probiotic bacteria to appreciate the therapeutic activity during fermentation and storage as well as the improved physico-chemical and sensory properties in parallel to the increased nutritional and antioxidant contents with addition of fruits. Therefore, fruit-based fermented drinks could be an alternative dairy product for the delivery of probiotic bacteria.