Physical-chemical and microbiological quality of fresh milk in the Southeast Region of Bahia

Abstract

This work evaluated the quality of fresh milk samples from 18 farms in the County of Vitoria da Conquista, Southwest of Bahia, Brazil. Assessments of the count of mesophilic and psychotropic bacteria followed the conventional methodology proposed by Normative Instruction 62/2003 from the Ministry of Agriculture, Livestock and Supply (MAPA). The physicochemical parameters (titratable acidity in degrees Dornic, alizarol alcohol stability, cryoscopic index) were evaluated according to the conventional methodology recommended by the Adolfo Lutz Institute. The analyses of fat, protein, defatted dry extract, and density at 15 °C, were performed using an ultrasonic milk analyzer. In addition to the physicochemical and microbiological characteristics evaluated, antibiotic residues were verified using penicillin G, tetracycline, chlortetracycline, and oxytetracycline detection kits. The results indicated that mesophiles were present in values ​​higher than that established (3.0 x 105 CFU / mL) in 50% of the samples of refrigerated raw milk, and approximately 11% of the samples were positive for the presence of antibiotic residue. For the parameters acidity, cryoscopy, dry extract defatted, and alizarol alcohol stability, irregularities were detected in at least 11.11% of the samples of raw refrigerated milk. The results indicated the need to take preventive measures, such as the education and qualification of professionals who deal directly with dairy cattle for greater guarantees of the quality of raw refrigerated milk.