Microbiological safety of Minas Frescal cheese (MFC) and tracking the contamination of Escherichia coli and Staphylococcus aureus in MFC processing

Abstract

Minas Frescal cheese (MFC) is a traditional food produced and consumed in Brazil, characterized by its soft texture, low sodium, and high moisture content. This study characterized the microbiological contamination by coliforms, Escherichia coli and Staphylococcus aureus, in 99 MFC samples obtained in retail sale and produced by three distinct industrial procedures. Dairy processors were selected to investigate the key points of E. coli and S. aureus contamination during cheese processing. MFC samples produced by the addition of lactic culture presented higher counts of coliforms and E. coli, when compared to other samples ( p < 0.05). MFC samples produced by the addition of rennet alone presented higher counts of S. aureus when compared to other samples ( p < 0.05). Fourteen of 19 MFC samples produced by the addition of lactic culture presented E. coli counts higher than 5 · 10 2 colon-forming units/g. The processing steps after pasteurization were identified as the main sources of E. coli and S. aureus contamination of MFC. Based on the results, MFC was characterized as a potential hazard for consumers due to the high frequency of samples contaminated with E. coli and S. aureus counts in non- compliance with Brazilian standards for sanitary quality and safety.