Microbiological analysis of raw milk, pasteurized milk and yogurt samples collected from different areas of Dhaka city, Bangladesh

Abstract

A total of 300 different milk and yogurt samples were collected from Dhaka city and analyzed for total viable bacterial count (TVBC), total coliform count (TCC) and presence of several pathogens such as Escherichia coli, Salmonella spp., Shigella spp., Vibrio spp. and Listeria monocytogenes. Raw milk samples collected from Moghbazar area showed highest TVBC (4.2 × 10 6 cfu/ml) and samples from Mohammadpur area showed lowest count (3.5 × 10 3 cfu/ml). All the pasteurized milk samples showed TVBC of 1.9 × 10 2 to 2.8 × 10 3 cfu/ml, and TCC only in one sample Yogurt samples (open) collected from vendor showed TVBC of 9.1 × 10 3 to 8.2 × 10 7 cfu/ml, and TCC only in sample collected from Dhanmondi, Dhaka. The packed yogurt samples showed TVBC of 2.2 × 10 2 to 6.1 × 10 3 cfu/ml, and TCC only in one sample. All the milk and yogurt samples were found contaminated with E. coli and Shigella-like species. Listeria monocytogenes was not detected in any of the samples studied.

Application of HACCP system to food preparation and services kitchens in Mansoura University hostels

“…In yoghurt samples, the finding of TBC according to table 2 does not agree with the reported range of TBC in examined yoghurt samples in other previous studies of [15]. Higher results were obtained by [16] due to the improper hygienic measures and heat treatment during yoghurt processing and manufacturing.…”

Hygienic Quality of traditional and industrial yoghurt produced in Qazvin province of Iran

“…An assessment in Bangladesh revealed that TCC only in one yoghurt sample (open) collected from vendor presented TVBC of 9.1× 10 3 to 8.2×10 7 cfu/ml and TCC only in a sample which was collected from Dhanmondi, Dhaka. The packed yoghurt samples showed TVBC of 2.2×10 2 to 6.1×10 3 cfu/ml and TCC only in one sample (12). Results of our study showed the evidence of microbial load increase in traditional yoghurt during summer, clearly.…”

“…staphylococcus aureus, E.coli, salmonella, pseudomonas spand Bacillus sp (11). Contaminated yoghurt can carry some health hazards (12). According to Institute of Standards and Industrial Research of Iran (ISIRI), the Yoghurt sample must not contain fungi more than 1 × 102 cfu/g, the coliform standard similarly lets the presence of less than 10 cfu/g of coliform bacteria and 0 cfu/g of E.coli and coagulase-positive staphylococcus.…”