Microbiological quality of pasteurized milk in west of Tehran (Winter 1391)

Milk as a unique source of elements is important in bone formation and its growth. In addition, it contains valuable proteins, minerals and vitamins. Considering the nutritional importance of this food and its role in personal health, microbial quality status of pasteurized milk was studied. In this research, microbiological quality of 60 pasteurized milk samples collected from western part of Tehran was evaluated by enumeration of aerobic mesophilic microorganisms, coliforms and detection of Escherichia coli. According to Iran's National Standard limits, aerobic mesophilic microorganisms and coliforms counts must not exceed 7.5×104 CFU/ml and 10 MPN/ml in pasteurized milk, respectively. Besides, Escherichia coli must be absent. Eighty five percent of the samples had satisfactory qualities. Escherichia coli was not isolated from any sample. The aerobic mesophilic microorganisms and coliforms counts were not in accordance with Iran's National Standard limits in 5% and 10.3% of the studied samples. Aerobic mesophilic microorganisms and coliforms average counts were 1.8×104 CFU/ml and 1.1 MPN/ml in the studied samples, respectively. The results confirmed satisfactory microbial quality of studied pasteurized milk samples.