A Multivariate Approach to Study the Bacterial Diversity Associated to the Wooden Shelves Used for Aging Traditional Sicilian Cheeses.

Raimondo Gaglio,Gabriele Busetta,Luca Settanni,Massimo Todaro,Giuseppe Licitra,Riccardo Gannuscio

doi:10.3390/foods11050774

Raimondo Gaglio, Gabriele Busetta + Show 4 more

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https://doi.org/10.3390/foods11050774

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Abstract

The present study was carried to correlate the microbial diversity of the biofilms developed on the wooden boards used for aging traditional Sicilian cheeses with cheese typology. To this end, the microbial diversity of the shelves in contact with the cheeses PDO Pecorino Siciliano, PDO Piacentinu Ennese, and TAP Caciocavallo Palermitano, during ripening, was evaluated by a multivariate statistical approach. The shelf biofilms of this study were previously analyzed for their microbial composition, but no correlation between biodiversity and cheese type was investigated. Canonical discriminant analysis confirmed a cheese typology effect on the microbial loads of the wooden shelves investigated. Regarding the plate count data, the centroids of different cheeses were statistically distant from one another. This analysis also showed a good graphic separation of data regarding bacterial order operational taxonomy units (OTUs). Thus, the microbiological differences imputed to the cheese typologies were not affected by the environmental conditions of the facilities. Furthermore, wooden shelf lactic acid bacteria (LAB) were investigated for their ability to inhibit the main dairy pathogens. Although inhibitors were mainly enterococci, P. pentosaceus WS287 and W. paramesenteroides WS581 showed the highest inhibition activity, indicating their possible application to control the undesired bacteria in situ.

Highlights

In the case of dairy products, cheeses, several works have demonstrated how microbial biofilms formed on the surface of wooden vats used for milk processing are responsible for curd acidification, cheese ripening, and even the inhibition of undesired bacteria attachment and development thanks to the massive presence of lactic acid bacteria (LAB) [8–14]
The use of wooden shelves in Sicily is mandatory for the ripening of several traditional semi-hard and hard cheeses, including protected denomination of origin (PDO) Pecorino Siciliano, PDO Piacentinu Ennese, and traditional agri-food product (TAP) Caciocavallo Palermitano [21]
The dual statistical approach applied in this study clearly showed that the microbial levels and the bacterial composition of the biofilms of the wooden shelves used to ripen traditional cheeses are influenced by the cheese typology

Summary

Introduction

Wood has represented the main material for the manufacture of dairy equipment in Europe for centuries [1]. In the case of dairy products, cheeses, several works have demonstrated how microbial biofilms formed on the surface of wooden vats used for milk processing are responsible for curd acidification, cheese ripening, and even the inhibition of undesired bacteria attachment and development thanks to the massive presence of lactic acid bacteria (LAB) [8–14]. Another wood equipment, the opentopped table (namely “mastredda”) used for curd acidification during Sicilian stretched cheese production, was analyzed for the composition of LAB biofilms, evidencing the presence of Enterococcus, Lactobacillus, Lacticaseibacillus, Lactiplantibacillus, Levilactobacillus, Lactococcus, Leuconostoc, Pediococcus, and Streptococcus [15]

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