Physical, chemical and microbiological properties of ayransproduced with addition of probiotic bacteria

In this research, probiotic bacteria cultivation was carried out in order to further increase the functionality and usefulness of ayran, which is a beverage consumed abundantly in the world, especially Turkish society. As a result, it is aimed to increase the contribution of probiotics to human health, to determine the positive or negative developments that may occur in the shelf life and to determine the environmental conditions in which probiotic bacteria can show their effects best. Both normal and probiotic cultures were added to full-fat cow and goat milk and stored at 4°C for 14 days. The amount of pH, dry matter, protein, oil, titratable acidity, flavorings and organic acid were examined on the 1st, 7th and 14th days of the storage period. Microbiologically, the total number of aerobic mesophil bacteria, total aerobic psychrophil bacteria number, yeast mold number, proteolytic bacteria number, lipolitic bacteria number, lactic acid bacteria number, Lactococcus type bacteria number, Lactobacillus acidophilus bacteria number, Bifidobacterium animalis spp. lactis bacteria number were investigated. While the pH value and viscosity of the samples decreased during storage, an increase in monounsaturated fatty acids occurred due to the use of probiotic bacteria in ayran production. It has been determined that the sample type has a very high level of effect on the amounts of benzoic acid, citric acid, succinic acid and lactic acid in Ayran. The use of probiotics culture in ayran production significantly increased the amount of organic acid in ayran. While the highest lactic acid was determined among the four organic acid varieties, higher lactic acid amount was found in ayran made from cow's milk. According to the results of microbiological analysis, the increase in the total number of live bacteria, which increased partially until the 7th day of storage in all samples, accelerated at the end of storage. While the total number of psychrophilic, lactic acid bacteria, yeast and mold numbers increased, Lactobacillus acidophilus, Lactococcus numbers and proteolytic bacteria numbers that were effective on the consistency, aroma and nitrogenous compounds of the ayran samples decreased during storage. The number of Bifidobacterium animalis spp. lactis, which was detected at a higher rate in ayran produced with goat milk at the end of fermentation, was not detected in cow and goat milk samples produced without probiotics and generally decreased. Finally, when looking at the results of sensory analysis, the appearance, smell, color scores decreased in the samples depending on the storage period, while the taste and consistency scores increased. General appreciation, on the other hand, increased in the first seven days and then decreased.