PHYSICOCHEMICAL AND MICROBIOLOGICAL QUALITY OF COW AND CAMEL MILK IN ERER WELDAYA DISTRICT, HARARI REGIONAL STATE, ETHIOPIA

Abstract

This study aimed to evaluate the quality of cow and camel milk based on physicochemical and microbial properties. A cross-sectional study design was employed to collect milk samples from Erer district from October to January 2022. A total of 75 milk samples were analyzed. The physicochemical parameters of the milk samples such as fat, specific density, freezing point, totalsolids, protein, solid non-fat, lactose, lactic acid, galactose, glucose, and urea content were determined using Milko Scan following the standard procedures. The pH of the milk samples was determined using a digital pH meter. The detection and enumeration of indicator bacteria E. coli (ECC), coliform (CC),total coliform (TCC), and aerobic plate count (APC) were determined by Petri film™ plates. The Yeast (YC) and mould count (MC) were determined using Potato Dextrose Agar (PDA) as culture media. The detection of S. aureus was conducted using Mannitol Salt Agar plate. The collected data were analyzed using GeneStat software version 18.0. The results demonstrated that cow milk samples from Dodota scored the lowest pH (5.9). The pH of most analyzed milk samples was within the acceptable limit set by the Ethiopian Standard Agency. A significant positive correlation on the physicochemical properties of cow milk was observed between fat and total solid (0.9254), and protein and total solid (0.6086). Likewise, a significant positive correlation in physicochemical properties of camel milk was also observed between fat and total solid (0.9200), solid nonfat and total solid (0.7591), protein and solid nonfat (0.7643), and density freezing point depression (0.6029). The prevalence of S. aureus was 34% and 25% in cow and camel milk, respectively. The mean loads of ECC (3.90 Log CFU/mL), CC (2.30 Log CFU/mL), TCC (4.18 Log CFU/mL), APC (5.22 Log CFU/mL), YC (4.89 Log CFU/mL), and MC (3.64 Log CFU/mL). The mean E. coli contamination in cow milk samples collected from Dodota was significantly (p < 0.05) higher compared to other kebeles. The mean coliform count in Semire (3.434 Log CFU/mL) was significantly higher (p < 0.05) compared to other locations. The aerobic plate count contamination of cow milk showed no significant difference (p> 0.05) across kebeles. The camel milk from Dodota recorded significantly the lowest E. coli count (1.33 Log CFU/mL) at p<0.05. The aerobic plate count contamination of camel milk was not significantly different (p > 0.05) across kebeles. The presence of pathogen like S. aureus and indicator bacteria during raw milk signifies poor hygiene practice and milk handling. Thus, appropriate milk handling practice is needed to ensure milk safety.