Search Results (130)

Background: Zoonotic infection with Mycobacterium bovis continues to occur, particularly in regions lacking bovine tuberculosis surveillance and where the consumption of unpasteurized dairy products, including artisanal cheeses, is common. We describe the clinical and microbiological characteristics, diagnostic procedures, and treatment outcomes of individuals with HIV with M. bovis infection. Methods: We conducted a retrospective study analyzing sociodemographic, clinical, microbiological, and computed tomography (CT) data, as well as treatment outcomes, in 12 patients with HIV with confirmed M. bovis infection. These findings were compared with those of 14 individuals with HIV diagnosed with Mycobacterium tuberculosis infection during the same period. Results: Consumption of unpasteurized dairy products was significantly associated with M. bovis. Patients with M. bovis infection had higher CD4+ T-cell counts compared to those with M. tuberculosis infection (p = 0.01, r = 0.45). All M. bovis cases presented with extrapulmonary disease. CT imaging in M. bovis infection more frequently demonstrated retroperitoneal lymphadenopathy, hepatosplenomegaly, and splenic abscesses compared to M. tuberculosis infection. Microbiological identification was exclusively from extrapulmonary sites in all M. bovis cases. Surgical interventions, including abscess drainage or splenectomy, were significantly more common among M. bovis patients. Conclusions: M. bovis infection in individuals with HIV is characterized by consistent extrapulmonary, often abdominal, involvement. Surgical procedures are frequently required for both diagnosis and management. Targeted efforts to identify M. bovis are warranted, particularly in high-burden regions where unpasteurized dairy consumption remains prevalent. Full article

Physico-chemical analyses, fatty acid profiles, microbiological analyses and sensory characteristics (assessed by trained judges and by consumers) were carried out on four types of goat cheese produced in artisanal cheese factories using raw milk from different autochthonous Spanish goat breeds (Malagueña, Florida, Murciano-Granadina and Cabra del Guadarrama). The cheeses studied were different in fat, protein, salt, pH, moisture, acidity and color due to the different production technologies and the properties of the milk of each breed. Saturated fatty acids (SFAs) were the predominant fatty acids in all the goat milk cheeses studied. Cabra del Guadarrama Cheese (CGC) and Malagueña Cheese (MC) showed an n-6/n-3 ratio < 4, and MC was found to have the lowest atherogenic and thrombogenic indices. CGC had a lower fat content than the rest of the cheeses studied. The fatty acid profile of CGC was more similar to MC than to Florida Cheese (FC) and Murciano-Granadina Cheese (MGC). MGC had a higher atherogenic and thrombogenic index, a higher PUFA n-6/n-3 ratio than the rest of the cheeses studied and a higher fat content. Therefore, CGC, MC and FC had a healthier lipid profile than MGC. The texture properties of CGC and FC were more similar to each other than to those of MC and MGC (harder cheeses). Sensory analyses performed with trained judges were in accordance with instrumental texture parameters. Consumer acceptability was similar for all the cheeses under blind conditions and only under informed conditions did consumers score FC significantly higher than MGC. In a rank test FC was chosen as the better cheese for a greater number of consumers both in blind and in informed conditions. The provision of information improved the overall liking of Cabra del Guadarrama Cheese and worsened that of Murciano-Granadina Cheese. The high quality of the cheeses confirms the need to raise consumer awareness of autochthonous goat breeds to increase the consumption of these products in order to contribute to the preservation of these breeds. Full article

A comprehensive characterization of two pressed-curd cheeses produced from ewe’s milk using enzymatic coagulation—Manchego cheese (with Protected Designation of Origin, PDO) and Castellano cheese (with Protected Geographical Indication, PGI)—was performed throughout the manufacturing process (industrial or traditional) and ripening stages (2, 9, 30, 90, and 180 days). Proton high-resolution magic angle spinning nuclear magnetic resonance (¹H HRMAS NMR) spectroscopy, combined with Principal Component Analysis (PCA) and cluster analysis, was applied to intact cheese samples. The combination of this spectroscopic technique with chemometric methods allows for the characterization of each type of sheep milk cheese according to its geographical origin and production method (artisanal or industrial), as well as the estimation of ripening time. The results demonstrate that HRMAS NMR spectroscopy enables the rapid and direct analysis of cheese samples, providing a comprehensive profile of their metabolites—a metabolic ‘fingerprint’. Full article

Requesón, a Mexican whey cheese, has a short shelf life due to its high moisture content, near-neutral pH, and the limited preservation infrastructure of the artisanal cheese sector. Therefore, the development of requesón powder provides an innovative pathway to enhance market potential and expand its applications. This study aimed to evaluate the techno-functional properties of requesón powder produced through air-convective drying and to assess the protective effects of two natural gums, mesquite gum and guar gum, at concentrations of 0.25 and 0.5 g/L. Thermal dehydration significantly affected (p < 0.05) water holding capacity, swelling capacity, and hardness of the reconstituted powder. Although gum addition did not significantly enhance water holding capacity, it moderately improved texture and led to notable increases in swelling capacity (21–34%) and emulsifying capacity (11–20%) at high concentrations (p < 0.05). Structural analyses using X-ray diffraction and electron microscopy revealed that thermal dehydration induced protein aggregation and reduced microporosity, impairing rehydration performance compared to requesón powder obtained by lyophilization. These findings suggest that requesón powder production is a promising strategy for valorizing whey and extending the applications of this traditional cheese as a functional food ingredient. Full article

In the Alpine region of Austria, Italy, and Switzerland, transhumance is widespread and the production of local traditional dairy products during summer is important. Raw milk cheeses are produced according to traditional recipes, using hurdles as a technique to guarantee food safety. In the present study, we aim to provide an overview of S. aureus and its enterotoxins in raw milk cheeses, identify the key parameters responsible for the enterotoxin production, and identify ways to improve food safety. The results demonstrate that safe artisanal raw milk cheese production is achievable under elementary conditions by applying effective hurdles, including high scalding temperatures or thermization, quality starter cultures, and robust milk quality management. The hurdle index (HI), which we introduce in this paper, is a promising tool for assessing and improving safety in raw milk cheese production. Full article

Listeriosis is a disease associated with the consumption of food contaminated with Listeria monocytogenes. Probiotic lactic acid bacteria (LAB) or their postbiotics have been of interest for their anti-listerial effect. This study focused on isolating LAB from artisanal cheeses and characterizing their potential as probiotics. Twelve LAB isolates exhibiting typical LAB traits were evaluated for their ability to survive in simulated gastric juice, hydrolyze bile salts, auto-aggregate, hydrophobicity, and antagonistic activity against L. monocytogenes. The four most promising LAB strains demonstrated anti-listerial probiotic potential and were identified as Latilactobacillus (Lat.) curvatus SC076 and Lactiplantibacillus (Lact.) paraplantarum SC291, SC093, and SC425. The antimicrobial activity of these strains was mainly attributed to bacteriocin-like substances and organic acids. While three Lact. paraplantarum strains were resistant to ampicillin, Lat. curvatus was sensitive to all tested antibiotics. All selected strains exhibited no hemolytic, gelatinase, and lecithinase activity. Exposure to LAB supernatants resulted in a significant reduction in the adhesion and intracellular count of L. monocytogenes in Caco-2 cells, with Lat. curvatus SC076 showing the most significant effect. Based on its probiotic characteristics, Lat. curvatus SC076 is a promising candidate for functional foods, pending further in vivo studies to assess its potential in the food industry. Full article

Donkey milk is well known for its beneficial properties for human health, making it a valuable ingredient in the production of value-added cheese. Rolled cheese, a type of pasta filata cheese, is traditionally produced in the northern part of Serbia. In this study, we produced rolled cheese by adding a certain amount of donkey’s milk from the Balkan and Banat breeds to cow’s milk. The rolled cheese samples were analyzed for their microbiological quality, chemical composition, content of essential and trace elements, as well as sensory characteristics. Adding 10% and 20% donkey’s milk had no effect on the microbiological quality or hedonic scale of rolled cheeses compared with rolled cheese made from raw cow’s milk. However, the addition of donkey’s milk partially affected the chemical composition and mineral profile of the cheeses. The fat, fat in dry matter, calcium contents, and the ratio of calcium and phosphorus significantly (p < 0.05) decreased with the addition of donkey’s milk, while the ash, salt, sodium, and potassium contents significantly (p < 0.05) increased. The assessors successfully distinguished the rolled cheeses containing donkey’s milk from those made with cow’s milk, encouraging the future production of value-added cheese. Full article

Buffalo milk is a rich source of precursor fatty acids for bioactive compounds and provides an optimal environment for bacterial growth. This study aimed to isolate and select lactic acid bacteria strains with potential to conjugated linoleic acid (CLA) production for technological application in fermented buffalo milk. Fifty-eight strains were isolated from raw milk, kefir, artisanal cheese, kombucha, and jaboticaba juice and tested for CLA biosynthesis. In milk fermentation, selected strains with linoleic acid (LA) conversion rates ranging from 65.66% to 21.86% were L. paraplantarum, L. plantarum, P. pentosaceus, and L. fermentum. The highest viability average values between 11.85 and 11.15 Log CFU/mL were observed after 8 h of fermentation for the L. plantarum, control L. plantarum, and L. fermentum treatments, while it took 10 h of fermentation for L. paraplantarum and P. pentosaceus to reach a stationary phase, with pH stabilizing at 4.60 ± 0.1 after 30 h. Despite L. paraplantarum showing the highest in vitro CLA production (0.99 mg/mL), in buffalo milk, all strains similarly produced c9t11 CLA, with no detectable t11c12 CLA. P. pentosaceus and L. fermentum showed a fatty acid profile with higher PUFA content, especially in CLA and MUFA, related to a lower degree of atherogenicity (IA) and thrombogenicity index (ThI). These findings boost understanding of dairy (raw milk, artisanal cheese, and milk kefir) and non-dairy substrates (kombucha and jaboticaba juice) as reservoirs for functional bacteria and highlight buffalo milk as a matrix for diversification of naturally enriched fermented dairy products. Full article

Citrobacter braakii can colonize the intestinal tract of humans and animals and occasionally act as opportunistic pathogen. Although isolated from food and the environment, its potential as a foodborne pathogen remains uncertain. Twenty C. braakii isolates were previously collected from salami and soft cheese artisanal productions. In the present study, the potentialities of C. braakii as a food safety hazard were explored by a genomic comparison of C. braakii newly sequenced genomes with publicly available genomes, including those of clinical relevance, and a pathogenicity assessment in Galleria mellonella as an in vivo infection model. Phylogenomic reconstruction revealed that one salami clone and two C. braakii genomes of the soft cheese production were closely related (from 11 to 28 core SNP differences) to C. braakii publicly available clinical genomes. All genomes carried the chromosomally located bla_CMY and/or qnrB genes and were resistant to cephalosporins and/or had reduced susceptibility to ciprofloxacin. G. mellonella larvae showed 90% mortality after challenge with C. braakii strains carrying the vex and tvi operons coding for the capsular polysaccharide (Vi antigen), in comparison to 40% of strains lacking these two operons. The high mortality rate of vex- and tvi-positive C. braakii isolated from food processing plants suggests C. braakii to be a possible foodborne hazard. Full article

Artisanal cheese microbiota plays a key role in defining its sensory properties, safety, and overall quality. Environmental factors, including altitude, influence microbial communities by altering temperature, pressure, and radiation levels, yet the extent of these effects on cheese microbiota remains unclear. Here, we investigated bacterial composition, diversity, and correlation patterns in artisanal cheeses produced along an 800 m altitudinal gradient in Southern Brazil using 16S rRNA gene sequencing and bioinformatic analyses. Diversity analysis showed no significant variation in microbial community structure across altitudes, suggesting that overall bacterial diversity is stable within this range. Physicochemical parameters, including moisture, pH, and fat content, also exhibited no statistical differences. However, differential abundance analysis revealed that while broad taxonomic profiles remained consistent, small differences were observed at deeper taxonomic levels, with Lactiplantibacillus, Psychrobacter celer, and Lactococcus raffinolactis showing altitude-associated variations. These findings suggest that altitude exerts only a subtle influence on cheese microbiota, primarily at lower taxonomic ranks. This study contributes to understanding environmental effects on cheese microbiomes, with potential applications for optimizing production and quality control in diverse altitudinal regions. Full article

This study evaluated the effects of adding the autochthonous cultures Limosilactobacillus mucosae CNPC007 (LM) and Lactiplantibacillus plantarum CNPC003 (LP), originally isolated from goat milk and goat cheese, respectively, on microbiological safety, microbiota composition (analyzed through 16S rRNA gene metataxonomic sequencing), and biogenic amine (BA) production in artisanal goat (coalho) cheese made from raw or pasteurized milk during 60 days of ripening at 10 °C. Six types of cheese were produced, varying in milk treatment (raw or pasteurized) and the presence or absence of LP or LM cultures. Adding either LP or LM significantly modulated the microbiota, favoring Streptococcus dominance and reducing overall bacterial diversity compared to non-inoculated cheeses. Raw milk cheeses with added autochthonous cultures exhibited a microbial profile like pasteurized cheeses, suggesting a homogenizing effect on the microbiome. Both cultures effectively reduced microbial load in raw milk cheeses after 20 days, reaching levels comparable to pasteurized cheeses by the end of ripening. Although BA concentrations increased over time, all samples remained within safe limits. Cheeses with LP addition exhibited lower BA levels, suggesting a modulating effect on their biosynthesis. Histamine concentrations were higher in raw milk cheeses with added cultures but remained well below hazardous levels. These findings suggest that incorporating either LP or LM strains is a promising strategy for enhancing the microbial safety and standardization of artisanal goat cheese while preserving its traditional characteristics. Full article

Artisanal cheeses face unique challenges due to changes in the present approaches to food safety, health, and environmental sustainability. This work aims at tackling such challenges in Pico cheese, by addressing outdated PDO criteria, the need to tackle coagulase-positive staphylococci (CoPS) and to promote circular economy by upgrading cheese whey. Model raw- and pasteurized milk cheeses were prepared with autochthonous lactic acid bacteria (LAB) as inoculants and analyzed for their composition, proteolysis, and microbiological parameters. CoPS were isolated and the risks they pose in terms of One Health evaluated by assessing phenotypic virulence factors and antibiotic resistance patterns. To assess the potential of autochthonous LAB for controlling CoPS, a challenge test was performed. Probiotic requeijão was prepared using autochthonous LAB as inoculants for upgrading whey. This work confirmed the need to update Pico cheese specifications regarding proteolysis indexes. Biofilm production was present in all Pico cheese CoPS, but resistance was only found against penicillin and cefoxitin. Adding salt or extending maturation time up to 60 days did not afford the desired level of CoPS control. Lactococcus lactis L1C21M1, however, was able to keep CoPS populations at 3 log cfu g⁻¹ in the challenge test. Requeijão was a suitable substrate for probiotic autochthonous Lactococcus lactis L3A21M1 and L3B1M7. Full article

Raw milk and traditional fermented foods such as artisanal cheese represent a natural source of lactic acid bacteria (LAB). They can produce antimicrobial compounds, such as bacteriocins and lactic acid, which may be exploited in dairy biopreservation. This study aimed to conduct a systematic review and meta-analysis to synthesize the inhibition diameter (ID) of LAB against L. monocytogenes, S. aureus, and Salmonella spp. Literature electronic searches were performed on PubMed, Scopus, and Web of Science, to identify articles that reported data on in-vitro antimicrobial activity by LAB isolated from dairy foods. A total of 1665 papers were retrieved, and 20 primary studies were selected according to the selection criteria, of which 397 observations were extracted. Random-effects meta-regression models were employed to describe the effects of LAB genus, pathogen concentration, susceptibility method, incubation time, inoculation volume, agar type and pH on the IDs for L. monocytogens, S. aureus, and Salmonella spp. L. monocytogens was the most susceptible pathogen (p < 0.05) to the LAB effects, followed by S. aureus and Salmonella spp. As a whole, LAB from the Lacticaseibacillus genus were the most effective (p < 0.05) in inhibiting L. monocytogens (21.49 ± 2.654 mm), followed by S. aureus (21.06 ± 2.056 mm). Salmonella spp. presented higher (p < 0.05) susceptibility to Lactobacillus genus (19.93 ± 2.456 mm). From the results, a general trend could be observed for the well-diffusion method to produce higher (p < 0.05) ID estimates than the spot and disk methods (30.73 ± 2.530 mm vs. 21.98 ± 1.309 mm vs. 13.39 ± 1.403 mm for L. monocytogenes; 22.37 ± 1.073 mm vs. 14.91 ± 2.312 mm vs. 20.30 ± 2.319 mm for Salmonella spp.), respectively. Among the tested moderators, the pathogen’s inoculum concentration, the in vitro susceptibility assay itself, incubation time and inoculation volume on agar are determinant parameters to be looked at when designing a robust and reproducible experimental plan. The in vitro results reinforced that LAB can be useful in controlling the development of pathogenic bacteria frequently found in the dairy industry. Full article

The present research evaluated the effect of selected Lacticaseibacillus casei strains with anti-Listeria monocytogenes properties on the characteristics of traditional soft-ripened cheeses produced in two different seasons. Physicochemical, microbiological, texture, volatile compound, and sensory evaluations were performed on the cheeses after 60 days of ripening. The inoculation with protective cultures of selected LAB did not negatively affect the physicochemical parameters of the cheeses. Thirty-two volatile compounds were identified, including acids, alcohols, ketones, aldehydes, and esters, with differences between productions and inoculated batches. The selected LAB strains improved the sensory profile of the soft-ripened cheeses, decreasing values of texture parameters such as hardness, gumminess, and chewiness related to a softer texture and increasing umami taste and floral and lactic odor attributes. Sensory analysis revealed that consumers perceived differences between inoculated and non-inoculated cheeses, although the overall acceptability was not affected. This study provides valuable information for the artisanal cheese industry, demonstrating that it is possible to use selected protective lactic acid bacteria to assure food safety without compromising traditional flavor and even improving sensorial attributes. Full article

Canastra cheese, an artisanal cheese produced in Serra da Canastra—Brazil, has great cultural importance. Furthermore, this cheese has nutritional and sensory attributes that make it of great economic importance. Its microbiota is composed of different bacteria and yeasts. Some yeasts already isolated by our research group have been characterized as potential probiotics. Probiotic microorganisms have garnered scientific interest, as improvements in the physical, chemical and sensory characteristics of food products have been reported when these microorganisms are used. In this context, the objective of this work was to evaluate Kluyveromyces lactis and Torulaspora delbrueckii, which were previously isolated from Canastra cheese, as autochthonous starter cultures. Canastra cheese was produced under three different conditions: (1) cheese with “Pingo” (natural starter), (2) cheese with “Pingo” + yeast mixed culture, and (3) cheese with only mixed yeast culture. The results showed that the mixed yeast inoculum significantly influenced the lactic acid bacteria population. Yeast populations remained at around 106 CFU/g after 45 days of maturation. Furthermore, cheeses containing the yeast mixed with inoculum had an initial lactose content reduced by 92.80% compared to cheese produced with “Pingo” (87.70%). The antioxidant activity, evaluated using the ABTS method, showed that cheeses containing the mixed yeast culture had higher percentages of antioxidant activity at 45 days of maturation. The texture profile of the cheeses changed over time. In general, the cheese containing the yeast mixed culture and “Pingo” and the cheese containing “Pingo” had the lowest hardness at 30 days of maturation (5245 and 5404 N, respectively). Among the volatile compounds, 3-methylbutyl octanoate, phenethyl butyrate, phenethyl propionate, isobutyl butanoate and pentyl propionate were found only in cheeses produced with yeast mixed culture. The obtained results demonstrated that the use of autochthones probiotic cultures could improve the cheese characteristics without negatively impacting the traditional physicochemical attributes of Canasta cheese. Full article