Determining some physical, chemical, microbiological and sensorial qualities of the milk produced from the different mixtures of skimmed buffalo milk and cow milk

The objectives of this research were to invastigate some physical, chemical, microbiological and sensorial qualities of the milk produced from the mixtures of skimmed buffalo milk and cow milk and to evaluate suitability of the findings to Turkish Food Codex Fermented Milk Notification and TS 1330 Yogurt Standard of Turkish Standards Institution. In addition, we aimed to evaluate the buffalo milk and skimmed buffalo milk for producing the yogurt. The yogurt samples have been stored at 4°C and analized on 0th, 3rd, 7th, 11th, 14th, 20th days of storage. The highest dry matter content (16.04%) was determined on 3th day of storage of the 5th sample and the lowest dry matter content (13.73%) was determined on 1st day of the storage at the 3rd sample. On the 0th day and 3rd day, we found the statistical difference among the avarages of the groups. On 7th, 11th and 14th days, we found no significant difference in the proportion of dry matter. The lowest fat content of yogurt samples (2.93%) was determined on 11th day of the storage of the 3rd sample while the highest fat content (4.07%) was determined on 1st day of the storage of the 4th sample. As a result of the statistical analysis, storage time did not differ significantly between the groups on the same day. On 20th day, we found the statistical difference between the avarages of the groups. Increases or decreases of the fat rates of the yogurt kept constant during the storage. The lowest protein content of yogurt samples (3.34%) was determined on the 20th day of the storage of the 1st sample, and the highest protein content (5.33%) was determined on the 3th day of storage of the 5th sample. As a result of statistical analysis, statistical difference on the 1st, 3rd, 7th, 14th days at the level of the P<0.01 were significant. On the 11th days at the level of the P<0.05, on the 20th days at the level of the P<0.001 statistical difference was highly significant. The lowest value of the separation of the serum of the yogurt samples (5.52 ml / 25 g.) was determined on the 7th days of the storage of the 5th sample while the highest value (10.94 ml/25gr.) was determined on the 7th days of the storage of the 1st sample. In the statistical analysis, on the 0th and 3rd days of the storage, there was no significant statistical difference between the groups, but on the 7th, 14th and 20th days of the storage at the level of the P<0.01, and on the 11th days of the storage at the level of the P<0.05 the statistical difference were significant. The highest titratable acidity value of yogurt samples were determined (1.90%) on the 20th days of the storage of the 5th sample while the lowest value (1.30%) were determined on the 0th days of storage of the 4th sample and at the 3rd days of the storage of the 1st sample. In the statistical analysis, on the 0th and 14th days of the storage, the statistical difference were significant at the level of the P<0,05. On the 3rd, 7th, 11th, 20th days of the storage, the statistical difference were highly significant at the level of the P<0.01. The highest pH value of yogurt samples (4.94) were determined on the first day of the storage of the 5th sample while the lowest value (4.18) was determined on the 20th day of the storage of the 3rd sample. Groups were statistically indistinguishable from each other during storage. Throughout the storage period there was no statistically difference between the groups in the microbiological analysis (P>0.05). Only on the 7th day of the storage, difference of the total number of mesophilic bacteria between the groups were found statistically significant. The lowest overall acceptability score (16.33) in the sensorial analyses was determined on the 11th day of storage of the 5th sample which produced from only the skimmed buffalo milk, the highest score (22.20) was determined on the first day of the storage of the 2nd sample which was produced from %75 cow milk and %25 skimmed buffalo milk. On the 0th, 3rd, 7th and 11th days when the sensorial analyses made, there was a significant difference among the groups (P?0.01). As a result, raw materials used in the production of yogurt has been found to be very important in terms of quality of the milk, yogurt and nutritional value. According to the data obtained from this study, yogurt which produced from different mixtures of milk have got difference about physical, chemical, sensory and microbiological properties.