Abstract

The aim of this study was to evaluate the microbiological quality of raw milk and coalho cheese commercialised in the Afrânio, Petrolina and Santa Maria da Boa Vista municipalities. The rural production of dairy products contributes significantly to the economy of these municipalities. We analysed 30 samples of raw milk and 30 samples of coalho cheeses. The microbiological quality was assessed by analysing total and thermotolerant coliforms, Escherichia coli, Listeria monocytogenes and Salmonella spp. High counts of the coliforms were detected in 86.7% of the raw milk samples analysed, and 80% of the samples had thermotolerant coliform counts above the levels permitted by legislation. E. coli was found in 66.7% of the samples, whereas 6.7% was contaminated with Salmonella spp. The total and thermotolerant coliform counts in coalho cheeses samples were 93.3 and 90%, respectively, which exceeded the standards permitted by law. In total, 80% were contaminated with E. coli and 20% with Salmonella spp. Listeria spp. was not detected in either the raw milk or the coalho cheese samples. Therefore, of the 60 samples analysed, 85% were not within the standards required by legislation. The implementation of good manufacturing practices is not only necessary to ensure the quality of products offered to consumers but also important for sustainability and food safety.

Key words: Dairy, coliforms, Listeria spp., Salmonella spp., food safety.

Abbreviation

MPN, most probable number;  LST, lauryl sulphate tryptose; EC, Escherichia coli broth; EMB, eosin methylene blue; TSA, trypticase soy agar; IMViC, indole-methyl red-Voges Proskauer-citrate; TSA-YE,  trypticase soy agar with 0.6% yeast extract; TSI, agar triple sugar iron; LIA, lysine iron agar; CFU, colony forming units; PCR, polymerase chain reaction; LAB, lactic acid bacteria; PCA, principal component analysis