Development and characterization of synbiotic kefir

In this thesis study; two different prebiotics [galactooligosaccharides (GOS) and inulin] were added to buffalo milk standardized to different fat ratios and synbiotic kefir was produced lefting grain or starter culture to fermantation. Fat, protein, serum separation, titration acidity, pH, total dry matter, water activity and total number of aerobic mesophilic bacteria, Lactococcus spp., Lactobacillus spp., Enterobacteriaceae, yeast numbers, antimicrobial activities and sensory properties of the produced kefir were analyzed on the 1st, 7th, 14th and 21st days of the storage. Protein, pH and dry matter values during storage; Production method, oil level, prebiotic addition and storage time were significantly (p<0.01) affected by the sources of variation. Fat value; It was significantly affected by the sources of variation: oil level, prebiotic addition and storage time. Storage time had a significant effect on the titratable acidity value, and prebiotic addition and storage time had a significant effect on the water activity value (p<0.01). As a result of microbiological analysis; It was determined that the use of starter culture and storage time were significantly effective on the development of lactic acid bacteria. It was determined that 0.5% fat level and culture use had a very significant (p<0.01) effect on the growth of total mesophilic aerobic bacteria. The development of yeasts, the effect of 3.5% fat level, inulin addition, traditional method and storage time was found to be significant. Antimicrobial activity gave the best results on the 21st day of storage. Sensory properties of kefir samples were found to be acceptable.