Análisis de presencia de antibióticos y la calidad de la leche cruda comercializada en diferentes mercados de la ciudad de Cuenca, Ecuador

Abstract

The present study is descriptive and prospective and was conducted in various markets in the city of Cuenca, Azuay province. A total of 96 raw milk samples were analyzed with the primary objective of evaluating their physicochemical properties, determining their quality and safety and detecting the possible presence of antibiotic residues. The physicochemical parameters were compared with the standards established by the Regulation of the Organic Law for the Promotion of Production, Commercialization, Industrialization, Consumption, and Price Fixation of Milk and Its Derivatives, as well as the NTE-INEN 09:2012 Standard. These regulations require that milk contain at least 3% fat and 2.9% protein, be free from adulterants and antibiotic residues, and comply with sanitary quality standards, such as a maximum of 250,000 somatic cells per milliliter. Therefore, parameters such as fat, protein, density, titratable acidity, total solids, non-fat solids, and freezing point were analyzed to identify differences between the samples obtained from different points of sale. The results showed that 1.04% of the samples tested positive for antibiotic residues, indicating a low level of contamination in informally marketed milk. Variables such as protein, fat, minerals, and non- fat solids exhibited low variability among samples from different markets. However, the analysis of somatic cell counts revealed that 55% of the samples exceeded the maximum limit permitted by the regulations, highlighting deficiencies in the sanitary quality of milk in several points of sale.