Microbiological aspects of the biofilm on wooden utensils used to make a Brazilian artisanal cheese

Abstract

The artisanal Minas cheese is produced from raw cow’s milk and wooden utensils were employed in its manufacture, which were replaced by other materials at the request of local laws. This substitution caused changes in the traditional characteristics of cheese. Due to the absence of scientific studies indicating the microbial composition of biofilms formed on wooden forms, tables and shelves used in these cheese production, the present work evaluated the counts of Staphylococcus aureus, Escherichia coli, coliforms at 32 °C, yeasts, presumptive mesophilic Lactobacillus spp. and Lactococcus spp. in these biofilms, milk, whey endogenous culture and ripened cheese in two traditional regions: Serro and Serra da Canastra. Also, we checked for the presence of Salmonella sp. and Listeria monocytogenes in the ripened cheeses. The ultra structure of the biofilms was also assessed. Counts above legislation (> 2 log cfu/mL) for the pathogens evaluated were found in milk samples from both regions. Only one shelf and one form from Serro were above limits proposed (5 cfu/cm2 for S. aureus and E. coli and 25 cfu/cm2 for coliforms) in this study for contaminants evaluated. In Canastra, few utensils presented safe counting of pathogens. There was no Salmonella sp. and Listeria monocytogenes in the cheeses after ripening. Thus, the quality of the cheese is related to improving the microbiological quality of milk, implementation and maintenance of good manufacturing practices, correct cleaning of wooden utensils, and not its replacement.

Microbial Safety of Wood in Contact with Food: A Review

“…For centuries, wood has been considered a natural package for the ripening of various food products, especially cheese. New food safety regulations are contributing to the substitution of wood by other materials, like polypropylene, high‐density polyethylene or stainless steel (Galinari and others ; Scatassa and others ). However, the replacement of wooden utensils by other materials changes the characteristics of cheese, affecting the traditional flavor and texture (Galinari and others ).…”

“…In Brazil, Galinari and others () analyzed the biofilm composition on wooden utensils used for the production of a Brazilian artisanal cheese: Minas. In fact, from 2002, the cheese makers had to respect new GMP in which wood was replaced by other materials.…”

Microbiological quality and safety assessment in the production of moderate and high humidity cheeses

“…However, there was no detection of this group of microorganisms in pasteurized milk samples (<0.3MPN mL -1 ), showing the pasteurization effectiveness process used by the dairies evaluated, which was confirmed by results of phosphatase (negative) and peroxidase (positive) tests. High levels of thermotolerant coliforms reported in raw milk samples analyzed can be related to deficient sanitary conditions of dairy farms or to hygienicsanitary problems in the milking process (MORAES et al, 2009;SOBRINHO et al, 2012;GALINARI et al, 2014;PIERI et al, 2014). Bacteria belonging to group of thermotolerant coliforms colonize mammals' intestine and their detection can indicate the presence of other pathogenic microorganisms of enteric origin.…”

Perfil microbiológico del queso de aro consumido en la Cañada Oaxaqueña

“…Los factores que producen inhibición de patógenos por parte de las bacterias ácido lácticas tenemos, la producción de H 2 O 2 , generación de ácidos orgánicos, producción de bacteriocinas, entre otras (PARRA-HUERTAS, 2010). Galinari et al (2014) obtuvieron un promedio igual al nuestro en quesos artesanales de Brasil. Pogačić et al (2010) mencionan que Lactococcus lactis es la bacteria ácido láctica predominante en queso artesanal elaborado con leche de oveja del este de Croacia.…”