Chemical and Microbiological Quality Assessment of Raw and Processed Liquid Market Milks of Bangladesh

Twelve different liquid market milks of Bangladesh were examined to evaluate their chemical and sanitary quality. Six of these were open raw milk bought from local daily markets and the other six were processed packet milk (both pasteurized and UHT (Ultra High Temperature)-processed) available in shops. The twelve samples were examined for the determination of percentage of water, total soluble solids, fat, solids non-fat, lactose, protein and ash, measurement of titratable acidity, detection of adulterants, enumeration of total bacterial count, staphylococcal count, coliform count, fecal coliform count, Salmonella and Shigella count, Aeromonas hydrophila count and psychrophilic count. Results revealed that most of the raw and pasteurized milks were substandard in both chemical and sanitary quality whereas the quality of UHT-treated milks was excellent. All the pasteurized and raw milks were found to be contaminated having bacterial load exceeding the acceptable limit. Pathogenic bacterial genera (Aeromonas, Salmonella and Staphylococcus) were identified in some of these samples. But none of the UHT-processed milk contained any bacteria. Water had been added in six samples whereas, sucrose was found in five of the six temperature-processed samples.