Occurrence of filamentous fungi isolated from matured blue cheese

Ocorrência de fungos filamentosos isolados de queijo azul maturado

Abstract

Matured blue cheese can be made from cow's milk associated with the inoculated fungus Penicillium roqueforti, which guarantees specific sensorial characteristics. Recently, Brazil’s fine cheese production and consumption have increased by more than 200%, highlighting the relevance of microbiological quality control of these products. Fungal contaminations are responsible for significant losses in cheese production and provide a suitable environment for mycotoxins production, constituting a hazard to public health. In this work, we evaluated the mycological contamination profile of matured blue cheeses commercialized in Brazil. Samples of ten different brands were analyzed by serial dilution method, by plating in the Dicloran Rose of Bengal Chloramphenicol (DRBC) culture medium and Dicloran Glycerol Medium Base (DG18). Subsequently, different fungi morphotypes were isolated and morphologically identified. As a result, 461 fungi were isolated and identified, notably Aspergillus aculeatus, Penicillium roqueforti and Penicillium solitum. All samples were contaminated by filamentous fungi, amongst those, many already reported as mycotoxin producers, which underlines the relevance of microbiological monitoring.

Keywords:
Aspergillus; Dairy; Food microbiology; Mycology; Food safety; Morphological characterization