Quality indicators and antibiotic residues in informally marketed raw milk from the central inter-Andean region of Ecuador

Abstract

Milk is a food of great nutritional importance; however, it can cause public health problems when not properly controlled.To determine the quality of raw milk marketed through informal commercialization channels (outside the formal dairy industry and routine quality control systems) in the central Inter-Andean region of Ecuador. To determine the quality of raw milk marketed through informal commercialization channels (outside the formal dairy industry and routine quality control systems) in the central Inter-Andean region of Ecuador. Overall, 98.32 % (527/536) of samples failed to comply with at least one quality criterion established by NTE INEN 9. Regarding physicochemical quality, titratable acidity and pH were the principal contributors to overall non-compliance, affecting 86.38 % and 82.46 % of samples, respectively. In terms of nutritional quality, lactose content showed the highest frequency of non-compliance (71.27 %). Elevated somatic cell counts and deficiencies in protein stability were observed in a substantial proportion of samples. Evidence of added water was identified in 28.17 % (151/536) of samples. Antibiotic residue screening tests detected residues in 15.49 % (83/536) of samples, with positive reactions to the sulfonamide screening assay representing 96.39 % (80/83) of all positive screening results. Significant differences among provinces were observed for several physicochemical, nutritional, and hygienic quality parameters. Overall, 98.32 % (527/536) of samples failed to comply with at least one quality criterion established by NTE INEN 9. Regarding physicochemical quality, titratable acidity and pH were the principal contributors to overall non-compliance, affecting 86.38 % and 82.46 % of samples, respectively. In terms of nutritional quality, lactose content showed the highest frequency of non-compliance (71.27 %). Elevated somatic cell counts and deficiencies in protein stability were observed in a substantial proportion of samples. Evidence of added water was identified in 28.17 % (151/536) of samples. Antibiotic residue screening tests detected residues in 15.49 % (83/536) of samples, with positive reactions to the sulfonamide screening assay representing 96.39 % (80/83) of all positive screening results. Significant differences among provinces were observed for several physicochemical, nutritional, and hygienic quality parameters.