مقارنة الطرق الميكروبية المستخدمة في الحكم على نوعية الحليب

Abstract EN

The methods used to judge the quality control of milk counting microscopic direct and this method can be fast distingish of cells and identify the source of microbial contamination , but it is difficult to distinguish between living and dead cells and that they do not give acceptable results for the heat treatment milk .

While the results showed in the way of standard plate count, although it is used along time of incubation they are calculated only living cells and the total count of bacteria less than in direct microscopic count range between 15 x 104 to 17 x 105 cfu/ml in the pasturide milk directly .

in direct microscopic count While the dyes reduction test gave unacceptable results due to rapid contamination in milk and the count of the bacteria ranged between 35x105 to 150x105cfu/ml then the number of the bacteria increase with the increase of the period of the storage .the relationship between the method dyes reduction test and the standard plate count to judge the quality of raw milk , as the samples were good at the 1 % level for statistical analysis while the samples stored when using the method of nitrates dyes reduction , the relationship level less than the quality of milk at a level of statistical analysis of 5 % in judging the quality of milk .the samples of the milk divided to two groups the first one contain bacteria less than 50 x 103 cfu/ml and the other contain more than 50 x 103 cfu/ml we find that the samples contain bacteria less than 50x103cfu/ml needs more time to reduce the pigments.