Determination of some physicochemical, microbiological and sensorial properties of the concentrated kefir produced from cow's milk with different production methods

In this study, concentrated kefir was produced by using different concentration methods. The aim of this study is to increase the viability of lactic acid bacteria and yeasts, to reduce the cost of storage and handling, to conserve the sensory properties of products for a long period by producing concentrated kefir. Milk powder addition to milk, evaporation of milk, evaporation of kefir and filtration of kefir by using american clothes are four different methods used in order to produce concentrated kefir. Kefir culture and kefir grains are two different cultures used for kefir production. Eight concentrated kefir samples with approximately 20% drymatter were produced and these samples were stored at 40C for 30 days. Physicochemical, microbiological and sensory properties of samples were determined at 1., 15. and 30. days of the storage . While titratable acidity and hardness values of samples were increasing, pH's of samples showed a decrease during storage. In addition, amount of lactobacillus, lactococcus, leuconostoc and acetic acid bacteria decreased during storage on the contrary yeast amount showed an increase. In concequence of the study, concentrated kefir produced by using american cloth was decided as the best of all according to sensory analysis.