Functional yoghurt production with kefir culture addition

In this thesis, it is aimed to investigate the production and acceptability of a functional yogurt produced with the addition of kefir culture. The interactions of beneficial microorganisms in yogurt culture and kefir culture in the same fermentation, changes in the sensory, physicochemical and technological properties of the product and their preservation of their vitality throughout the shelf life of the product were investigated. For this purpose, fermentations at different temperatures were also examined and an optimum production recipe was created, and it was tried to determine the stages of the microbiota in these two functional products reaching the market/consumer with a single product. For this purpose, incubation with 3% yogurt culture at 42°C-45°C (Sample A), incubation with 2% yogurt culture + 1% kefir culture at 42°C-45°C (Sample B) and 2% yogurt Three different products were produced as culture + 1% kefir culture and incubation at 35°C-37°C (C sample) and stored at +4°C for 21 days. Sensory, physicochemical and microbiological properties of yoghurts produced on the 1st, 7th, 14th and 21st days of storage were determined. As a result of the research, the dry matter values of the samples were found between 15.72-16.76%, and the oil values between 4.20-4.50%. Viscosity values are between 58.00-248.66 mPa.s, serum separation values are between 6.86-10.23 ml/25g, titration acidity is between 0.83-0.98%, pH is between 4.11-4.72 has also been detected. While the highest average value of Lactobacillus counts was 9,12 cfu/ml (log10) in B sample, the highest average value of Lactobacillus counts was 8,63 cfu/ml (log10) in A sample, the highest average yeast count was found in the C sample with 6.10 cfu/ml (log10). The highest average value of A sample with 4.91 in terms of appearance, sample B with 4.58 in terms of consistency, sample A with 4.42 in terms of odor, sample A with 4.17 in terms of taste, sample A with 4.67 in terms of total acceptability have been found to have. Keywords: Kefir, Yoghurt, Functional Food, Probiotic, Microflora