Assessment of the physicochemical properties of raw milk in Addis Ababa and its surrounding areas, Ethiopia

Milk is a highly nutritious food and an important source of income for smallholder farmers in Ethiopia. Ensuring the safety and quality of raw milk is essential for public health and consumer confidence. However, milk quality may deteriorate along the dairy value chain due to poor handling, storage conditions, and possible adulteration practices. This study assessed the physicochemical characteristics of raw cow milk collected along the dairy value chain in and around Addis Ababa, Ethiopia. Between June and September 2022, milk samples were obtained from four dairy-producing areas, Sebeta, Sheno, Sululta, and Bishoftu, and transported to the Veterinary Drugs and Feed Administration and Control Authority (VDFACA) laboratory for analysis. A Lactoscan milk analyzer was used to determine key physicochemical parameters including fat, solids-not-fat, protein, lactose, density, freezing point, and mineral content. Data were analyzed using two-way analysis of variance (ANOVA) at a 95% confidence level, and results were compared with standards established by the Ethiopian Standards Agency (ESA). The mean fat percentages of milk from Sebeta, Sheno, Sululta, and Bishoftu were 2.621 ± 0.967, 2.429 ± 0.838, 2.147 ± 1.026, and 2.602 ± 0.689, respectively. Milk obtained from farms, collectors, and cafeterias had mean fat contents of 2.831 ± 1.023, 2.419 ± 0.650, and 2.099 ± 0.835, respectively. Significant differences were observed in fat content along the value chain ( P = 0.017), while no significant differences were found among the study locations ( P > 0.05). Several physicochemical parameters were below ESA minimum limits. The lower quality of milk at the consumer level suggests possible adulteration, including water addition and fat removal. The study identified a progressive decline in several physicochemical quality indicators of raw milk along the dairy value chain. These findings are consistent with possible dilution, cream removal, or other handling-related factors; however, direct evidence of adulteration was not assessed. The results highlight the need for improved milk quality monitoring, stronger regulatory oversight, and further studies incorporating microbiological and adulterant detection analyses.