Yeasts and hygienic-sanitary microbial indicators in water buffalo mozzarella produced and commercialized in Minas Gerais, Brazil

Abstract

The aim of this work was to study the yeast populations and the main hygienic-sanitary microbial indicators in water buffalo mozzarella produced and commercialized in Minas Gerais, Brazil. Forty-two water buffalo mozzarella samples were purchased from retail outlets in Belo Horizonte. In addition, five samples of consecutive starter cultures, curd before acidification, acidified curd and mozzarella were collected at an industry in the city of Oliveira. Only three of the five water samples analyzed were suitable for consumption according to Brazilian sanitary standards. Four milk samples were highly contaminated with fecal coliforms, and did not meet the minimal hygienic-sanitary standards according to Brazilian regulations. Only one sample of buffalo muzzarela purchased from retail outlets exceeded the limit for coagulase-positive Staphylococcus. Eleven samples showed counts of thermotolerant coliforms higher than 5 × 103 CFU.g−1, but still lower than the maximum permitted by the Brazilian laws. Salmonella spp. and Listeria monocytogenes were not isolated. Debaryomyces hansenii, Candida lusitaniae and C. parapsilosis were the prevalent yeast species isolated from cheese. Among samples from the production stages, the acidified curd presented the highest numbers of yeasts, with C. catenulata being the most frequent species isolated. Some opportunistic yeast species such as C. guilliermondii, C. tropicalis, C. parapsilosis, C. lusitaniae, C. catenulata, C. rugosa and C. krusei occurred in the mozzarella cheese samples analyzed. The mozzarella cheese presented a low microbial load as compared to other cheese already studied, and the yeast biota included species typical of cheese and also opportunistic pathogens.

Development and characterization of two novel formulations of Labneh cheese of sheep’s milk

“…In a study with freshly produced Labneh buffalo cheese, the average value for molds and yeasts was 7.53 log CFU/g (Salem et al, 2013), higher than that observed in formulation L. In this Labneh cheese, there was no growth of molds and yeasts in day 1 and 15 of storage, probably because the formulation contained leaves of a plant with antifungal and antimicrobial properties (Salem et al, 2013). The results found in three different commercial brands of buffalo mozzarella cheese were lower than that found in the present study and ranged from less than 0.48 to 0.80 log CFC/g (Facchin et al, 2014). In a study carried out with bovine milk cheese containing very high humidity, the counts were 6.35 and 7.21 log CFU/g, at 15 and 30 days of maturation (Vasek et al, 2013), comparable to the formulation L2.…”

“…between 1.95 and 4.45 log CFU/g (Nespolo & Brandelli, 2012). In three commercial brands of buffalo mozzarella cheese, the values found for S. aureus ranged from 0 to 4.98 log CFU/g (Facchin et al, 2014). The evaluation of Salmonella sp.…”

“…In a study carried out with bovine milk cheese containing very high humidity, the counts were 6.35 and 7.21 log CFU/g, at 15 and 30 days of maturation (Vasek et al, 2013), comparable to the formulation L2. Yeasts are able to grow in milk and dairy products, due to their ability to assimilate and ferment lactose, assimilate citric and lactic acids, produce lipases and extracellular proteases (Facchin et al, 2014).…”

Microbiota “Fingerprint” of Greek Feta Cheese through Ripening

“…Their presence indicates poor sanitation [58]. Candida lusitaniae (2 isolates) and Kluyveromyces lactis (3 isolates) are opportunistic yeasts, considered as spoilage but mozzarella cheese, where Candida lusitaniae is part of the natural microbiota counting 4-6 log cfu/g [59,60]. Corynebacterium species (two isolates) are aerobic microorganisms usually growing on the surface of the cheese [61] and hence the presence of C. flavescens in the core of a cheese sample is probably due to cracks and breaches.…”

Genome analysis of the yeast Diutina catenulata, a member of the Debaryomycetaceae/Metschnikowiaceae (CTG-Ser) clade

“…Candida catenulata is an ascomycetous yeast, commonly associated with dairy products such as milk [ 1 ] and cheese [ 2 , 3 ], including in Ireland [ 4 ]. The species has also been isolated from the microbiota of the oral cavity of female canines [ 5 ], and from the gastrointestinal tract and the feces of poultry [ 6 ], wild birds [ 6 , 7 , 8 ] and piglets [ 9 ].…”