Some Microbiological Properties of Kefir Yogurts Produced by Using Milk Powder and Whey Powder

The purpose of this research is to evaluate the recycling of whey and gaining cost using demineralized whey powder as a dry additive instead of or in combination with milk powder in the food sector and to emphasize the importance of kefir in terms of health by increasing interest in kefir yogurt. Therefore, kefir yogurts produced by using different proportions of skim milk powder and demineralized whey powder as three replicates (A (control): kefir yogurt produced using 0% demineralized whey powder and 3% milk powder, B: kefir yogurt produced using %1 demineralized whey powder and 2% milk powder, C: kefir yogurt produced using 2% demineralized whey powder and 1% milk powder, D: kefir yogurt produced using 3% demineralized whey powder and 0% milk powder). Some chemical properties of milk powder and whey powder used in the production were determined, pH and titration acidity analyses of samples were carried out during incubation and microbiological properties were determined during storage. According to the results obtained, during the incubation, the kefir yogurt; pH and titration acidity values of kefir yogurt were significantly influenced by the incubation time (p<0.05) while the effects of milk powder and demineralized whey powder were not significant (p>0.05) on titration acidity and pH values. Storage time affected statistically significant effects (p<0.05) on total aerobic mesophilic bacteria and total yeast count while the effects of milk powder and demineralized whey powder were not significantly (p>0.05) on microbiological properties of kefir yogurt.