Document Type : Articles
Authors
College of Agriculture, Dohuk University, Dohuk, Kurdistan region, Iraq
Abstract
This study was conducted to the identification of microbial species isolates that contaminated yoghurt samples and to determine the viable microbial total counts, also the coliform counts, staphylococcus, lactic acid bacteria (LAB) and the fungi counts, in addition to the pH levels after storage the samples for 7 or 30 days in refrigerator temperature at 5 ºC from eight dairy factories in Dohuk city. The results were shows that the total viable microbial counts significantly increased (p<0.05) and appeared between log 6.25 to 9.25 CFU/ml after the end storage period, while, the LAB significantly decreased in all yoghurt samples and became between log 4.23 to 4.60 CFU/ml, compared with the counts at initial storage at between log 8.14 to 12.20 CFU/ml. The coliform, Staphylococcus and fungal isolates were found only at the end of yoghurt samples storage periods and some of its samples were not to detected in its. The range of pH for all yoghurt samples at the end of storage periods was 3.62 to 4.05 compared with the range at the initial storage periods at 3.97 to 4.40. The microbial isolates from yoghurt samples were the Staphylococcus sp., E. coli, Klebsiella sp. and Pseudomonas luteola, lactobacillus bulgaricus, Aspergillus sp., Penicillium sp., and the yeast in all of the samples. Also, it that appears some bacterial isolates were completely resistant to antibiotics
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