Butter adulteration practices and their health risks were assessed along the supply chains in the central highlands and southwestern midlands of Ethiopia. A purposive sampling technique was used to select 1,101 respondents. Based on the results of the cross-sectional study, fatty acid profiles of butter samples collected from retailers' shops were investigated to determine the extent of adulteration and understand the risks of food safety. The assessment showed that an average of 94% of the respondents were aware of practices of butter adulteration. The common butter adulterants identified include different brands of hydrogenated vegetable oils, Irish potato puree, banana pulps, melted tallow, wheat and maize dough, and buttermilk, as well as water. The practice of adulteration significantly differed (P < 0.05) along the supply chain and increased from farm markets to the retail shops. Economically motivated adulteration is the main cause and resulted in up to 50% of butter spoilage. There were significant differences among the fatty acid profiles of pure butter; retailers' butter; pure butter intentionally adulterated with hydrogenated oil, potato puree, and banana pulp; and pure hydrogenated oil. The presence of methyl oleate, gondoic acid, and eicosadienoic acid in the retailers' butter might result from adulteration with hydrogenated oils and banana pulps. The study showed the presence of multiple-stage adulteration along the supply chain that could endanger the safety and quality of local butter. Policymakers and regulatory bodies in the area can use the information to improve the safety and quality of local butter along the supply chain.
The butter adulteration rate increases (20 to 30%) as it moves along the supply chain.
On average, 94% of supply chain respondents were aware of butter adulteration practices.
Hydrogenated vegetable oil, banana pulp, and potato puree were among the adulterants.
The fatty acid profile of the samples confirmed the presence of adulteration.
50% of butter spoilage is linked to adulteration practices with identified materials.