Indicator microorganisms as indices of quality for milk and some dairy products

الملخص EN

A total of 150 samples including raw cow's milk, pasteurized milk, small scale ice cream, large scale plain and flavored yoghurt (30 of each) were collected randomly from dairy shops, super markets and small scale ice cream producers in fayoum city, Egypt and examined for sanitary and microbiological status.

the result revealed that the mean value of titratable acidity % in plain and flavored yoghurt were 1.41± 0.02 and 1.67±0.04, respectively.

the mean values of total coliforms were 7.5×105± 3.9×105, 8.25×102± 5.04×102, 8.2×104±4.1×104, 4.83×102 ± 3.15×102 and 2.72×103± 9.5 ×102 cfu/mlorg., respectively.

while the mean values of faecal coliforms were 2.8×104± 1.5×104, 1.16×102 ± 7.11×10, 1.02×103 ±1.71×102, 2.01×10± 1.07×10 and 3.13×102±1.30×102 cfu/mlorg., respectively.

the mean values of e.coli were 1.38×103± 6.89×102,1.84×10 ± 9.5, 4.87×102±1.18×102, 1.36×10± 8.4 and 4.68×10± 1.50×10 cfu/mlorg.

the mean values of enterococci were1.12×106± 1.29×105, 2.1 ×103± 4.20×102, 1.1 ×106 ±1.87×105, 2.23×103± 6.29×102 and 7.77×103±1.67×103 cfu/mlorg., respectively.

staph.

aureus was detected in the examined raw cow's milk and small scale ice cream samples, with the mean values of 1.98×105 ± 3.91×104 and 7.65×104 ± 2.41×104 cfu/mlor g., respectively, but was not detected in the other samples.

total yeasts and moulds were detected in the examined large scale plain and flavored yoghurt samples with mean values of 1.15×10²± 3.59×10 and 4.48×10²± 8.17×10 (cfu/mlor g.), respectively.