Properties of honey and propolis yogurt produced using different cultural types and prebiotic sources

The aim of this thesis study is to examine the effects of prebiotic sources such as 2% almond and hazelnuts powder added to yoghurts produced by using probiotic starter cultures that additional yoghurt starter culture, as well as effects of bee products such as 4% honey and 0,25% propolis on the properties of starter cults and products during their shelf life. Dry matter, pH, titration acidity, protein, fat, ash, lactose, antioxidant (DPPH inhibition), total phenolic substance, color, texture, viscosity, sensory and microbiological analyzes were made in yogurt samples. Dry matter values of yoghurt samples produced are 17.48-19.56%, pH values are 4.05-4.48, lactic acid values are 0.86-0.99%, protein values are 4.16-4.39%, fat values are %2.8-4, ash values ranged between 0.88-1%, total carbohydrate values ranged between 9.13-11.56%. 21. during the daily storage period, DPPH inhibition values of yoghurt samples were 51.95-65.13%, total phenolic substance values were 3.11-3.75mgGAE/g, color values were L*: 85.7-90.6, a*: -0.10-1.29, b*: 5.93-12.22, texture values were 46.89-72.06g, viscosity values in the range of 18974.25-26269 mPa.s, taste, appearance, color, consistency, structure (sensory) scores were measured as 6.17, 7.22, 7.37, 7.12, 7.16 out of 9 full points, respectively. As a result of the microbiological analyzes carried out during the 21 day storage period, S. thermophilus numbers 8.66-9.21, L. delbrueckii subsp. bulgaricus numbers 8.05-8.89, L. acidophilus numbers 8.15-8.82, L. casei numbers 6.93-7.18, B. lactis numbers varied between 6.38-7.08 log cfu/g. As a result, it was determined that probiotic microorganisms and yogurt starter cultures maintained their viability at a level of at least 6 log cfu/g during the storage period. The antioxidant properties of the developed product were found to be sufficient when compared to other studies. It can be said that the effects of prebiotic sources, propolis and honey on the viability of probiotic microorganisms are positive.