Microbial Quality Evaluation of Raw and Pasteurized Cow Milk in Wolaita Sodo Town, Southern Ethiopia

Abstract

Enhancing hygiene practices and the microbiological quality of milk can significantly strengthen Ethiopia's dairy supply chain. However, producing hygienically safe milk presents a considerable challenge in the country's dairy sector, where milk and milk products are frequently processed under unsanitary conditions. Hence, this study aimed to assess the microbial quality of raw and pasteurized cow milk in Wolaita Sodo town, southern Ethiopia. A total of 100 milk samples (70 raw and 30 pasteurized) were collected from dairy farms and retail shops for microbial analysis following standard procedures. The analysis included total bacteria count (TBC), total coliform count (TCC), and the detection of Escherichia coli. The results indicated no significant variation (P>0.05) in total bacteria count among raw milk samples from the three kebeles, with an average of 4.75±0.12 log10 cfu/mL. However, the total coliform count was notably higher (P<0.05) in raw milk from Merkato (3.80±0.15 log10 cfu/mL) compared to Ofa Gandaba (3.22±0.14 log10 cfu/mL) and Fana kebele (3.19±0.13 log10 cfu/mL). In the pasteurized milk samples, total bacteria count and total coliform count showed no significant differences (P>0.05) across the three brands, though brand Y exhibited a higher mean total coliform count (3.73±0.89 log10 cfu/mL) than brands X (2.9±0.89 log10cfu/mL) and Z (3.18 ± 0.77 log10cfu/mL). Escherichia coli was found in 35.7% of raw and 33.3% of pasteurized milk samples. These findings reveal significant bacterial contamination in both raw and pasteurized milk, including zoonotic pathogens, underscoring the urgent need for improved dairy product safety.