Quality of raw milk produced in agreste region of Pernambuco, Brazil

Abstract

The poor quality of raw milk is the main problem in dairy industries, once it can directly interfere in the productivity and quality of dairy products. The Pernambuco is not different. located between the Zona da Mata and the Sertão regions, is responsible for a daily milk production of 980,000 liters, and presented an increase of 23% in the last two years. This study aimed the evaluation of the microbiological and physical-chemical quality of raw milk produced in the Agreste region of Pernambuco. Raw milk samples were collected from 53 dairy farms located at the following cities: Saloá, Águas Belas, São Bento do Una and Bom Conselho. For microbiological analysis, all samples were plated for mesophilic aerobes, total coliforms, Escherichia coli and DNase positive staphylococci in specific Petrifilm™ (3M Microbiology, St. Paul, USA). Listeria monocytogenes and Salmonella spp. were detected using VIDAS system (bioMérieux SA, Marcy l'Etoile, France). Organophosphorade and carbamates were detected by  thin layer chromatography. Fat, protein, and lactose contents, total and non-fat solids, and density were obtained by ultrasound method using am automatic milk analyzer (Boecolac-60, Boeco, Hamburg, Germany). In addition, the raw milk samples were evaluated to cryoscopic, California Mastitis Test (CMT), peroxidase, Dornic acidity and Ring-test to brucellosis status of herds. In microbiological analysis, all samples presented high counts of the researched indicators microorganisms. The average of mesophilic aerobes was 1.68 X 10⁷ with 83% of samples over 10⁶. Listeria monocytogenes and Salmonella spp were not found, 47% of the samples were positive for organophosphates and/or carbamates, 67.9% of the samples were positive for CMT and 26.4% for ring test. Thus, only 2 (3.77%) samples were accordance with the established parameters of Instrução Normativa 51.