Characterization of Artisanal Minas Cheese produced in the region of Serra da Canastra: fungal diversity and volatile compounds profile

Abstract

Artisanal Minas Cheese is a traditional cheese produced in several regions of the state of Minas Gerais, Brazil. This type of cheese is developed in a simple way though techniques introduced by Portuguese settlers and it constitutes one of the main economic activities of several families that rely on family agriculture. In the state of Minas Gerais, seven regions are registered in the Artisanal Minas Cheese Program. Among them, Serra da Canastra is highlighted due to the popularization of its cheeses, which are regulated for the use of the Indication of Origin (IP) "Canastra". In artisanal Minas cheese, the environmental conditions of region such as precipitation rate, temperature and humidity affect the microbiological community, generating influences on safety, singularity, quality and nutritional factors. Thus, the terroir microbiota present in a specific region direct the characteristics of the product. There is little scientific information about this cheese, and the culture value, the economy importance and the increased of international visibility justify this product as an important object of research. The aim of this study was to characterize the fungal diversity and the volatile compounds profile present in this protected Indication of Origin cheese. The fungal community of the samples were investigated by culture-dependent approaches (culturing, morphological identification and MALDI-TOF). Moreover, the method of solid-phase micro-extraction gas chromatography mass spectrometry (SPME-GC) was applied to determinate the characteristics volatile compounds of this cheese. Complex fungal diversity and volatile compound profile was observed. The fungal diversity analyses revealed the presence of 37 different species of yeasts and molds. It was able to identify Fusarium sp., Cladosporium cladosporioides (complex), Acremonium sp., Trichotecium sp., Aspergillus versicolor, Aspergillus niger and Plenicillium glabrum in all samples. However, each sample demonstrated a unique fungal diversity composition, as Candida catenulata, Geotrichum candidum and Aspergillus versicolor were the major species in the sample P1, P2 and P3, respectively A total of 66 compounds were detected: 15 acids, 12 alcohols, 23 esters, 9 ketones, 3 aldehydes, and 4 miscellaneous compounds which could not be classified in these groups. The acids were the most important group identified, with hexanoic acid, octanoic acid and decanoic acid being the most abundant. The fatty acids present in maturated cheese contribute to cheese aroma, by their aromatic proprieties or being precursors of alcohols, esters, ketones, and others compounds. Our results therefore show that future studies should verify the exact contribution of each fungus to the volatile compound profile on Canastra cheese.