Microbiological characteristics of canastra cheese during manufacturing and ripening

Abstract

Canastra cheese is an artisanal product from the Serra da Canastra region in Brazil. It is produced with raw milk and an endogenous culture called pingo. Brazilian legislation requires 22 days of ripening to ensure microbiological safety. This study evaluated the microbiological characteristics of samples collected in two settings. In the first, samples were harvested along the manufacturing process (including milk, pingo, curd and cheese at different ripening times) from three producers registered in the state's quality program. In the second setting, cheese samples were collected from 78 local producers, after ripening. All samples were assessed for total coliforms, Escherichia coli, coagulase positive Staphylococcus and submitted to pH measurement. Enterobacteriaceae, Salmonella spp., and Listeria monocytogenes were tested in cheeses from the second setting, in addition to aw measurement. Results collected during cheese production indicated that the regulatory microbiological limits related to counts of total coliforms, E. coli and Staphylococcus could be reached before 22 days. Conversely, the study with cheeses collected from a larger pool of producers (samples with 22 days of ripening) showed a high number of non-compliances to the Brazilian regulation, regardless of registration in the quality program. Counts of coagulase positive Staphylococcus were above the legal limits in many samples, one was positive for L. monocytogenes, while Salmonella was not detected. The pH and aw were not good indicators of safety, as none of these parameters correlated with microbial counts. There is a need for improvements in the good manufacturing practices in the Canastra cheese production chain. © 2020 Elsevier Ltd