Minas Artisanal Cheese Research Articles

The taste of a champion: Characterization of artisanal cheeses from the Minas Gerais region (Brazil) by Raman spectroscopy and microstructural analysis

The production of artisanal cheeses is an important economic activity in different regions of Brazil, especially in Minas Gerais. In this work, 25 samples of artisanal cheeses were collected during the Ninth State Contest of Artisanal Minas Cheese from seven microregions (Canastra, Serro, Araxá, Campos das Vertentes, Serra do Salitre, Triângulo Mineiro and Cerrado). The Raman spectra of all analysed samples showed changes in the spectral pattern mainly in the 3050–2770 cm−1 region, i.e. bands from lipids, implying the main differences between the artisanal cheeses can be attributed to lipid quantity. SEM analysis, showing the structural images of the surface of all the artisanal cheeses, made it possible to observe the different characteristics in the samples. The major contribution of this study is the demonstration that Raman spectroscopy can be used to analyse qualitatively and quantitatively artisanal cheeses, as well as to understand the real chemical composition of a champion cheese.

Further culture-independent characterization of the lactic microbiota of Serro artisanal cheese.

This study aimed to provide a further characterization of the lactic microbiota present in Minas artisanal cheese (MAC) from the Serro region by using culture-independent methods, as a complementary analysis of a previous study. The total DNA extracted from MAC samples (n = 55) was subjected to repetitive extragenic palindromic-PCR (rep-PCR) and PCR-denaturing gradient gel electrophoresis (PCR-DGGE). Rep-PCR analysis showed that core microbiota of Serro MAC was closely related, independent of the production town, farm size, or time of production. The sequencing of PCR-DGGE bands identified the prevalence of Lactococcus lactis in all samples, and Streptococcus salivarius was also identified. Thus, we conclude that when more accurate methods are unavailable, rep-PCR can be used as a culture-independent method to demonstrate if the microbiota is closely related or not among the samples. PCR-DGGE results also matched to the main findings of high-throughput sequencing, previously presented, confirming its confidence to detect the main microbial groups present in the raw milk cheeses.

Minas Artisanal Cheese As Potential Source of Multidrug-Resistant Escherichia coli.

Bacteria develop resistance to antibiotics naturally, but the inappropriate and widespread use of antibiotics in humans and animals has made antimicrobial resistance one of the biggest threats to modern medicine. Raw milk cheese can represent an important source of antimicrobial resistance. Thus, the objective of this study was to evaluate the prevalence and sensitivity of Escherichia coli isolated from artisanal cheese made from raw milk produced in Minas Gerais, Brazil. E. coli counts were determined using the most probable number method. An antibiogram was performed using the disk diffusion method, following the protocol described by the Brazilian Committee on Antimicrobial Susceptibility Testing (BrCAST) for 14 antibiotics of nine classes. E. coli was detected in 35 (71.4%) of the samples, with populations between 0.56 to 4.87 log (NMP/g) of cheese. The presence of E. coli resistant to multiple antimicrobials was more frequent in cheeses, with an E. coli population below the levels established by regulatory limits. Only four samples (11.4%) had all E. coli isolates susceptible to the 14 antimicrobials evaluated. The results showed the heterogeneity of antimicrobial resistance in E. coli between the producing regions of Minas artisanal cheese. Multidrug resistance was detected in 29% of the E. coli isolates and in almost 40% (38.8%) of the cheese samples. The frequency of multidrug-resistant (MDR) isolates was different between the production regions (p < 0.05). The presence of MDR E. coli in cheese from region D was 14, 4, and 20 times more likely than in cheese from regions A, B, and C, respectively. A multiple antibiotic resistance index of 0.200 predicted the presence of MDR E. coli in raw milk artisanal cheese with 99% probability. In conclusion, artisanal cheese can act as sources of MDR E. coli to colonize the human gastrointestinal tract.

Staphylococcus aureus from Minas Artisanal Cheeses: Biocide Tolerance, Antibiotic Resistance and Enterotoxin Genes

Staphylococcus aureus is a common contaminant in artisanal raw-milk cheeses. Tolerance of S. aureus to biocides is a threat to disinfection in the cheese production environment, while antibiotic resistance and enterotoxin production are additional health concerns. This study aimed to evaluate the tolerance of S. aureus isolated from Minas artisanal cheeses to the biocides benzalkonium chloride, hexadecylpyridinium chloride, cetrimide, triclosan, hexachlorophene, and chlorhexidine, and the simultaneous occurrence of genes coding for antibiotic resistance (mecA, aacA-aphD, and tetK), efflux pumps [qacA/B and smr (qacC/D)], and enterotoxins (sea, seb, sec, sed, see, seg, seh, sei, and sej). Among the tested isolates, 38.2% were resistant to at least one biocide, and 73.1% were positive for one or more antibiotic resistance gene. Most of the biocide-tolerant and antibiotic-resistant isolates harbored efflux pump genes, and were positive for at least one staphylococcal enterotoxin gene. The study highlights the need for correct hygiene monitoring programs to ensure the safety of these products.

Characterization of the Lipid Profile of Artisanal Minas Cheese from Different Certified Regions in Brazil: An Exploratory Study

Characterization of the Lipid Profile of Artisanal Minas Cheese from Different Certified Regions in Brazil: An Exploratory Study

Effect of storage on physico-chemical, microbiological and sensory characteristics of goat milk fermented by Lactobacillus strains isolated from minas artisanal cheeses

Lactobacillus spp. are lactic acid bacteria which have important implications for the food industry due to their fermentation capacities. The aims of this research were to produce fermented goat milks with Lactobacillus plantarum B7 and Lactobacillus rhamnosus D1, isolated from Brazilian artisanal cheeses, and to evaluate their physico-chemical, microbiological and sensorial qualities during 30 days of storage at 7°C. The goat milks, fermented by B7, D1, co-culture and a Lactobacillus casei Shirota control, possessed acceptable physico-chemical characteristics to meet fermented milk standards established by Brazilian legislation and maintain the viability of Lactobacillus spp. throughout the shelf life of the products. The products were microbiologically safe. D1 fermented goat milk gave higher consumer sensory quality acceptance and purchase intention (p&lt;0.05) than other treatments, thus Lactobacillus rhamnosus D1 is recommended for fermented goat milk production.

Effect of storage on physico-chemical, microbiological and sensory characteristics of goat milk fermented by Lactobacillus strains isolated from minas artisanal cheeses

Lactobacillus spp. are lactic acid bacteria which have important implications for the food industry due to their fermentation capacities. The aims of this research were to produce fermented goat milks with Lactobacillus plantarum B7 and Lactobacillus rhamnosus D1, isolated from Brazilian artisanal cheeses, and to evaluate their physico-chemical, microbiological and sensorial qualities during 30 days of storage at 7°C. The goat milks, fermented by B7, D1, co-culture and a Lactobacillus casei Shirota control, possessed acceptable physico-chemical characteristics to meet fermented milk standards established by Brazilian legislation and maintain the viability of Lactobacillus spp. throughout the shelf life of the products. The products were microbiologically safe. D1 fermented goat milk gave higher consumer sensory quality acceptance and purchase intention (p<0.05) than other treatments, thus Lactobacillus rhamnosus D1 is recommended for fermented goat milk production.

Assessing the Microbiological Safety Parameters of Minas Artisanal Cheese Samples in Retail Environments in São Paulo, Brazil

Minas artisanal cheese is the best known and most consumed type of cheese in Brazil. Prepared with raw bovine milk and starter cultures, these cheeses face many opportunities for post-processing contamination during their transport to commercial establishments as well as in how they are stored, displayed, and maintained for cutting/slicing at retail establishments. It is a common practice for retailers to purchase entire cheeses from the producers, cut them into smaller pieces for retail sale, and store them at room temperature instead of properly refrigerating them. This study evaluated the microbiological safety parameters of samples of Minas artisanal cheeses collected at retail establishments in the city of São Paulo, Brazil, to more realistically assess consumer exposure to the most common pathogens. Samples were submitted for investigation of Salmonella spp., Listeria monocytogenes, and the counts of total coliforms, Escherichia coli, and coagulase-positive enterotoxigenic staphylococci using culture and real-time PCR methods. A worrisome number of samples failed to comply with the current Brazilian legislation for foods in retail environments and presented more than one non-compliance issue. Results highlighted that quality and safety management tools, such as good hygiene practices and HACCP, in retail environments deserve more attention to reduce the possible risks to consumer health.

Lactic microbiota of the minas artisanal cheese produced in the serro region, Minas Gerais, Brazil

The lactic microbiota of the Minas artisanal cheese (MAC) produced in the Serro region was characterized by culture-dependent and -independent methods. Samples of Serro MAC (n = 55) were obtained and plated for lactic acid bacteria (LAB) enumeration. Isolates (n = 176) were subsequently identified by 16S rRNA sequencing as lactobacilli, Lactococcus lactis and Enterococcus sp. LAB counts and the distribution of identified species did not differ by producer city, producer farm size, starter culture and time of production (P > 0.05). DNA from samples was subjected to high-throughput 16S rRNA sequencing and L. lactis was the predominant species in all samples. Alpha-diversity indices (species number, diversity, richness) and beta-diversity analysis did not differ between samples (P > 0.05). Core microbiota for all cheese samples included L. lactis, Streptococcus salivarius, S. thermophilus and Acinetobacter johnsonii. Here, we were able to show that lactobacilli and L. lactis are the dominant lactic groups and species in the Serro MAC, supporting the establishment of a typical microbial signature for this cheese.

Different types of packaging influence sensory profile of Canastra artisanal cheese

Artisanal cheeses have been highly appreciated by consumers, and have an important social, economic and cultural significance in Brazil. However, problems related to the chemical and sensory changes resulted from the microorganisms metabolism during the storage have been pointed. Product shelf-life and quality can be influenced by the product packaging. Thus, this work aimed to evaluate the influence of different types of packaging on the sensory profile of Canastra artisanal minas cheese; and associate its sensory profile to the main bacterial groups present in the cheeses under each type of packaging. Cheeses from a same batch with 14 days of maturation were packed in VACUUM, NYLON MESH, BUTTER PAPER, PVC FILM and without packaging until 22 days of maturation. Cheese`s Sensory profile and Microbial diversity were evaluated. Packaging used in Minas artisanal Canastra cheese maturation promoted different sensory attributes. PREMAT and BUTTER PAPER were the preferred samples, followed by the cheeses submitted to VACUUM PACKAGING, NYLON MESH, and PVC FILM. POSTMAT was less preferred. However, all samples had good acceptances. attributes such as sour flavor, mild flavor, butter flavor, farm flavor, salty, cured, compacted and soft drove the PREMAT acceptance. Moreover, this sample presented Lactococcus sp (OTU24), Corynebacterium sp (OTU25), Lactobacillus plantarum (OTU26), Streptococcus sp (OTU27), Lactobacillus plantarum (OTU28), Lactobacillus brevis (OTU22) and Lactobacillus casei (OTU13). Although the different sensory profile provided by the different packages, everyone showed to have market potential. The results of this study provide important information for the artisanal cheese producers focusing on product quality improvement and conservation.

Molecular Detection of Coxiella burnetii in Unstandardized Minas Artisanal Cheese Marketed in Southeastern Brazil

Q fever is a zoonotic disease caused by Coxiella burnetii. The causative pathogen has been detected in dairy products, which raises the possibility of consumption of dairy products as a possible route of transmission; however, this has not been adequately described. Therefore, the aim of the present study was to investigate the presence of C. burnetii in 87 samples of artisanal cheeses made from unpasteurized raw milk sold in Minas Gerais, southeastern Brazil. The cheese samples were analyzed using quantitative real-time PCR (qPCR), and the products from positive samples were sequenced. In addition, 150 people were interviewed to outline the profile of consumers and the consumption of non-inspected dairy products. The results showed that 4.6% (4/87) of the samples were positive for C. burnetii, with 99.84% identity with the reference 16S gene. Responses from consumer interviews indicate that 95.3% (143/150) of respondents consume milk and dairy products; 50% (75/150) consume fresh Minas artisanal cheese and milk at least once a day; 64.58% (93/144) do not check the inspection stamps on the packaging at the time of purchase; and 81.56% (122/146) do not know the meaning of these stamps. Thus, the presence of C. burnetii DNA in the analyzed cheeses and the consumption of unstandardized dairy products raise an alert for the risk of transmission of Q fever in the population that consumes them.

Mycobiota of Minas artisanal cheese: Safety and quality

The physicochemical characteristics of ripened Queijo Minas Artesanal (QMA; Minas artisanal cheese) and the mycobiota present in the air in cheese-ripening rooms and in the QMA were evaluated. The fungal population was identified by phenotypic characterisation and matrix-assisted laser desorption ionisation-time of flight mass spectrometry. Physicochemical analyses showed average values of humidity, sodium chloride, fat and lactic acid were 33.6%, 0.1%, 31.1% and 2.5%, respectively, and pH 6.3. A total of 280 isolates were obtained. The main species present in the air were Penicillium commune, Scopulariopsis spp. and Fusarium solani. The most prevalent fungi in the cheese were Debaryomyces hansenii, Yarrowia lipolytica, Candida zeylanoides, Kluyveromyces lactis, Cladosporium cladosporioides (complex) and Penicillium roqueforti. Notably, the species D. hansenii, Geotrichum candidum, Y. lipolytica, C. zeylanoides and K. lactis are important for the sensory characteristics of the product. Risk species such as Aspergillus flavus that are potential producers of aflatoxins have been detected.

A importância das bactérias láticas na segurança e qualidade dos queijos Minas artesanais

O queijo Minas artesanal é um produto que possui aroma, textura e sabor únicos, além de sua produção fazer parte de toda uma tradição e cultura familiar. O leite cru, matéria prima para fabricação desse queijo, possui naturalmente microrganismos benéficos, conhecidos como bactérias ácido-láticas, responsáveis pelas características organolépticas e segurança microbiológica do queijo, uma vez que produzem diversas substâncias durante sua maturação, inclusive antimicrobianas, que podem ser antagonistas de patógenos. A seguinte revisão apresenta informações sobre a atividade antagonista das bactérias láticas e sua capacidade de garantir a segurança e qualidade do queijo artesanal.

Use of diaries as a research strategy on sensory perception and consumer behavior of Canastra cheese

AbstractThe diary method has been used in some areas of knowledge, being uncommon in the area of sensory analysis of food. In addition, given the expanding market and the added value of Canastra artisanal Minas cheese, it is important to study consumer behavior, as well as understand the consumption habits of the product. Thus, the objective of this study was to use the diary method to collect sensory data, in addition to investigating the behavior and perceptions of consumers of artisanal Minas cheese. Potentials and weaknesses of the application of the method were discussed. The results of this study will contribute to sensory science, focusing on the assessment of real and continued food consumption. Moreover, they provide a better understanding of consumer behavior and consumption habits of artisanal Minas cheese from Canastra, directing planning production, marketing and commercialization strategies.Practical ApplicationThe findings of this study are useful for Brazilian artisanal cheese producers as it enables understanding the consumer behavior and consumption habits of artisanal cheese to plan production, marketing, and commercialization strategies. In addition, it shows practical utility for consumer‐based methodologies, focusing on the assessment of real and continued food consumption.

Microbial shifts through the ripening of the “Entre Serras” Minas artisanal cheese monitored by high-throughput sequencing

Minas Gerais is a Brazilian state known as the largest cheese producer in Brazil. Minas Artisanal Cheese (MAC) is produced in different regions of this Brazilian state using raw cow milk to which a natural starter culture (“pingo”) is added. “Entre Serras” is one of these regions, in which the MAC production had decreased (even stopped) for decades until recently, when artisanal cheeses production has been resurrected. Here, we aimed to gain insights on the bacterial diversity of “Entre Serras” MAC. 16S rRNA gene amplicon sequencing was used to assess the bacterial community in cheeses produced by four farms (A, B, C, and D) over 60 days of ripening. Overall, Lactococcus lactis was the predominant species found, regardless of the producer/farm. Enterococcus, Streptococcus, Lactobacillus and Leuconostoc genera were also prevalent in the samples microbiota and their levels varied according to the producer/farm. Cheeses produced by Farms A and B presented high contaminant levels (mainly Enterobacteriaceae and S. aureus), which may be attributed to poor hygiene during cheese production and/or herd health management. Chao1 indices varied significantly when the estimated species richness values of the producers/farms were compared (p < 0.05). A principal coordinate analysis also revealed distinct microbial communities for some farms (p < 0.001). However, no statistical significance was identified when samples were grouped by ripening time. Core microbiota analysis indicated that “Entre Serras” MAC microbiota includes not only LAB, but also spoilage and potentially pathogenic bacteria. We provide the first insights on the bacterial diversity of “Entre Serras” MAC, helping the understanding of the inter-regional microbiological diversity of the samples.

Natural starter culture on artisanal cheese

The use of natural starter culture in the manufacture of artisanal Minas cheeses is required by the government legislation in Brazil. However, there are no scientific support on role of the natural starter culture in these cheeses. The aim of this work was to compare artisanal Minas cheeses produced with and without natural starter culture to verify the influence on the physico-chemical and microbiological characteristics during the ripening process. The use of natural starter culture did not have a significant effect on the physico-chemical (dry matter, humidity, fat, pH, chlorides, water activity, ash, total protein, depth and extent of proteolysis) and microbiological (Escherichia coli, coliforms and Staphylococcus aureus) properties of the cheeses. The significant changes that occurred in the cheeses were mainly because of the ripening time. According to obtained results, natural starter has shown to be innocuous to traditional Minas Serro cheese. The present study is pioneering in the scientific literature and opens new horizons for the understanding of the requirement to use natural starter culture.

Brazilian artisanal cheeses are rich and diverse sources of nonstarter lactic acid bacteria regarding technological, biopreservative, and safety properties—Insights through multivariate analysis

In this study a total of 220 isolates of lactic acid bacteria (LAB) recovered from 10 types of Brazilian artisanal cheeses marketed in 4 main regions of Brazil were evaluated regarding their safety and ability to produce diacetyl (a precursor of aromatic compounds), exopolysaccharides (EPS; from different sugar sources), and antagonistic activity against Listeria monocytogenes and Staphylococcus aureus. The results indicated that 131 isolates (59.6%) were classified as strong (40.5%) and moderate (19.1%) diacetyl producers; 28 isolates (12.7%) stood out due to their remarkable production of EPS from different sugars, including sucrose (3.2%), fructose (2.3%), lactose (2.3%), and glucose (6%). Furthermore, 94.1% and 95.9% of isolates presented antagonistic activity against S. aureus and L. monocytogenes, respectively, even though only 27 isolates (12.3%) exhibited positive results in the bacteriocin production test. None of the isolates tested presented hemolytic activity, and 117 were classified as safe, due to their intrinsic resistance to a maximum of 4 different antibiotics. The data obtained for assessment of antibiogram profile and technological potential (moderate and high production of diacetyl, EPS, and bacteriocins) were submitted to a multiple correspondence analysis to correlate them with the cheese of isolation. Regarding the antimicrobial profile of LAB strains, it was possible to verify an association between isolates from Minas artisanal cheeses from Araxá and resistance to tetracycline; Minas artisanal cheeses from Serro and resistance to erythromycin; Coalho and Minas artisanal cheese from Cerrado and resistance to penicillin; and isolates from Serrano and Colonial cheeses with clindamycin and ceftazidime resistance. Although the susceptibility of strains to these antibiotics was considered high (71.8-80.5%), these data may be related to the horizontal transfer of genes in the production chain of these cheeses. Results of multiple correspondence analysis also showed that isolates with antagonistic activity were mostly isolated from Manteiga, Colonial, and Coalho cheeses. The isolates with high or moderate EPS-producer ability from sucrose, glucose, and fructose were mainly associated with Minas artisanal cheeses from Cerrado. In contrast, isolates with high or moderate EPS-producer ability from lactose were isolated from Serrano, Minas artisanal cheeses from Canastra, and Campo das Vertentes microregions. Finally, isolates from Minas artisanal cheeses (from Araxá microregion), Coalho, and Caipira cheeses were associated with moderate/high diacetyl production. To the best of the authors' knowledge, this study provides, for the first time, data indicating that the dominant technological, biopreservative, and safety properties of LAB isolates can be correlated with the type of Brazilian artisanal cheeses, which denotes its singularity. This knowledge is of utmost relevance for the development of starter or adjunct cultures with tailored properties.

QUEIJO MINAS ARTESANAL PRODUZIDO NA REGIÃO DE CANASTRA: CARACTERÍSTICAS DOS PARÂMETROS DE PRODUÇÃO, QUALIDADE DA ÁGUA E DOS QUEIJOS

The Serra da Canastra region is known for the production of a characteristic Minas artisanal cheese, named Canastra cheese. The objective of this study was to characterize the microbiological and physicochemical aspects of the water and cheese collected from the Minas artisanal cheese producing properties, as well as to characterize the environmental aspects of cheese manufacturing. The analyzes were carried out by private laboratories and the government in 2016 and 2017 and the results provided were tabulated and analyzed in the present study. In the physical chemical analyses of the water, the highest non-conformity was for free residual chlorine (44.69%). In the microbiological analyses of the water, 17.02% of the samples showed non-conformity for E. coli and total coliform parameters. In the microbiological analyses of the cheese, non-conformities were found in 7.84% of the samples for total coliforms at 30°C and 9.8% for coagulase-positive Staphylococcus spp. The physicochemical analyses of the cheese were all in compliance. No statistical association was found between the quality of the cheese and the water. The water sources were protected, however discard of the waste from cow pens, sanitary sewage, and garbage is still not properly handled. The study indicates that producers need to improve the quality control of the water supply for their cheese factories, fulfill the requirements of chlorine in the water and periodically verify this requirement, ensuring that the produced cheese is safe for human consumption.

The complex microbiota of artisanal cheeses interferes in the performance of enumeration protocols for lactic acid bacteria and staphylococci

We assessed the interference of a complex food microbiota, present in Minas artisanal cheese (MAC) produced in the Serro region, on the performance of enumeration protocols for lactic acid bacteria (LAB) and staphylococci. Initially, 140 isolates were obtained from 6 Serro MAC samples and plated for enumeration of LAB (3 variations of MRS, M17 and Petrifilm™ LAB) and staphylococci (Baird–Parker and Petrifilm™ STX); some target isolates did not grow or present atypical morphologies in their selective protocols. Then, Serro MAC samples (n = 55) were obtained and plated for LAB and staphylococci based on the same protocols: 2569 isolates were obtained from LAB and 1164 from staphylococci protocols: Petrifim™ LAB presented the highest frequencies of LAB-confirmed colonies, as Petrifilm™ STX for staphylococci (p < 0.05).

Enterococcus spp. in Brazilian artisanal cheeses: Occurrence and assessment of phenotypic and safety properties of a large set of strains through the use of high throughput tools combined with multivariate statistics

Traditionally fermented food generally has unique sensorial aspects due to its high microbial diversity, being broadly consumed worldwide. Despite this, some Vancomycin-Resistant-Enterococci (VRE) can occur in these products, which raises questions about their safety. Thus, this study tries to assess information about the occurrence of Enterococcus strains in traditional Brazilian cheese samples collected from the five main regions as well as the characterization of their phenotypic (proteolytic, lipolytic and bacteriogenic potential) and safety (hemolysin activity and growth at commercial VRE selecting media) aspects. A total of 1669 lactic acid bacteria were isolated, of which 605 (36.2%) were identified as Enterococcus by 16sRNA sequencing. Out of these, E. faecium (58.7%) was identified as the dominant species, followed by Enterococcus faecalis (31.8%), Enterococcus durans (4.8%), Enterococcus hermanniensis (1.6%) and Enterococcus gilvus (1.6%). All the data were analyzed by multivariate statistics, and the findings highlighted the presence of Enterococcus as a naturally component of indigenous microbiota of Brazilian artisanal cheeses, mostly in the cheeses of Marajó, Coalho, and Manteiga, possibly as a consequence of their heat resistance and the curd cooking step applied during the process in these regions. The majority of the identified Enterococcus (63.1%) did not produce β-hemolysin and were not resistant to vancomycin. Interestingly some of these strains (21.4%) were able to inhibit Listeria monocytogenes ATCC 35152, mostly isolates from Serrano, Colonial, and Minas artisanal (from Cerrado microregion) cheeses. Also, 10.2 and 11.8% of them have shown moderate to high proteolytic and lipolytic activity, respectively. Anti-listerial activity is of most interest as it can contribute to reduce risk of listeriosis due to dairy products consumption, while proteolysis and lipolysis are responsible for some remarkable features (e. g. flavor, taste, and texture) of fermented foods. In summary, this study represents a contribution towards revealing some phenotypic and safety traits of a large set of strains of Enterococcus strains through the use of multivariate statistics combined with high throughput tools.