Some Lactobacillus strains may contribute to the health of the host when administered in adequate concentrations, demonstrating their probiotic potential. In contrast, Listeria monocytogenes is a foodborne pathogen that can cause enteropathy, meningoencephalitis, abortion, and septicemia. The aim of this survey was to evaluate the in vitro and in vivo probiotic potential of Lactobacillus plantarum B7 and Lactobacillus rhamnosus D1, isolated from Minas artisanal cheese of the Serra da Canastra (Minas Gerais, Brazil), against Lis. monocytogenes. We submitted B7 and D1 to in vitro testing (antibiogram, tolerance to bile salts and artificial gastric fluid, and spot-on-lawn) and in vivo testing (relative weight gain in mice). Both Lactobacillus strains demonstrated in vitro inhibitory activity against Lis. monocytogenes, as well as sensitivity to antimicrobials and resistance to gastric acids and bile salts. In the in vivo assays, mice treated with D1 gained more weight than mice in the other groups. These results indicate that D1 could have higher probiotic potential than B7 because improvements in feed conversion may help animals fight infection.

A total of 480 milk samples were analyzed in four repetitions with four preservative treatments (no preservative, Bronopol, Bronolat and Brononata), three storage times at temperatures up to 4 °C (24, 48 and 72hours after reception), five different water additions (0.0, 2.5, 5.0, 7.5 and 10.0%) and two analytical instruments (electronic cryoscope and FTIR). The objective of this study was to evaluate the effect of these parameters in the determination of the freezing point by the reference method and by Fourier transform infrared spectroscopy, thus determining the best analytical conditions and establishing a mathematical equation for electronic determination by FTIR spectroscopy. Bronolat was the best preservative and Brononata was the worst and is not recommended to analyze freezing point by FTIR. The storage time of the samples did not interfere in the analytical determinations by the precision method and by FTIR.

O presente estudo avaliou o potencial probiótico in vitro de bactérias ácido-láticas (BAL) isoladas de queijo artesanal da Serra Geral (MG), com 14 e 21 dias de maturação, leite cru e pingo, utilizados em sua elaboração, e de bancadas de produção. As bactérias foram submetidas aos testes de antibiograma, à tolerância a ácido gástrico artificial e a sais biliares e ao antagonismo contra micro-organismos indicadores. Levilactobacillus brevis (Q521) e Lactococcus lactis (LLSG) apresentaram os melhores resultados e foram selecionados para a produção de leite fermentado. Apenas LLSG foi capaz de fermentar o leite. O produto apresentou qualidade microbiológica e físico-química adequada, exceto para os teores de proteína, segundo a legislação vigente para leites fermentados, demonstrando potencial tecnológico. A partir dos resultados apresentados, sugere-se que testes in vivo sejam realizados para que LLSG possa vir a ser utilizado como probiótico.

Introduction: Minas artisanal cheese is produced from raw milk. Legislation establishes a minimum 22-day ripening period for the cheese from Campo das Vertentes region. However, the lack of studies does not allow to attest whether this period is adequate to comply with the parameters. Objective: Based on this, the aim of this survey was to evaluate the microbiological and physicochemical quality of these cheeses throughout the ripening period at rainy and dry seasons. Method: Cheese samples throughout ripening were collected at four cheesemaking facilities, and were submitted to microbiological and physicochemical analyses. Results: The quality of cheeses was influenced by the ripening period and counts of coliforms at 45°C and molds and yeasts were affected by the season. Conclusions: The results met the official legislation requirements for cheeses at 60 and 22 days of ripening at rainy and dry seasons, and demonstrate the need for improvements in the control of coliforms and Staphylococcus.

This study aimed to evaluate the microbiological quality of Brazilian dry-cured loin (Socol), as well as the presence of ochratoxin A (OTA) and its synthesis by the isolated Aspergillus ochraceus complex under different conditions (culture media, temperature, and time of incubation). Nine bacterial genera were isolated and identified by Matrix Assisted Laser Desorption Ionization—Time Of Flight/Mass Spectrometry (MALDI-TOF/MS), including Serratia spp. (32.4%), Citrobacter spp. (20.9%), Enterobacter spp. (13.6%), and Staphylococcus spp. (6.3%), among others. Salmonella spp. was not observed, and counts of thermotolerant coliforms and coagulase-positive Staphylococcus were below the confidence level. Fifteen fungal strains were isolated and identified as Aspergillus spp. (n = 5), Cladosporium sp. (n = 1), and Penicillium spp. (n = 9). OTA was quantified in Socol samples, and the enumeration of fungi showed a correlation (r = 0.77) with the mycotoxin detection. A. ochraceus complex produced OTA in Czapek Yeast Autolyzed (CYA) and Yeast Extract Sucrose (YES) agars at different times and temperatures. It was concluded that the microbiota of Socol is complex, encompassing spoilage bacteria. Undesirable fungi are also present, including those belonging to the A. ochraceus complex that produce OTA.

Socol is an artisanal meat product typical of Southeast Brazil. It is made from pork loin and ripened at room temperature. This work aimed to isolate, quantify, and identify lactic acid bacteria (LAB) in Brazilian dry-cured loin (Socol) as well as evaluate their in vitro probiotic potential. LAB were found in high amounts, varying from 2.5 × 10³ to 9.2 × 10⁶ CFU g⁻¹. Eleven isolated bacteria were identified by Matrix-Assisted Laser Desorption Ionization–Time-Of-Flight/Mass Spectrometry (MALDI-TOF/MS). Of these, six strains (Latilactobacillus brevis SFC1A, Latilactobacillus sakei SFC2A, Latilactobacillus curvatus SFC6A, Pediococcus acidilactici SFC9A, Latilactobacillus curvatus SFC11A, and Pediococcus pentosaceus SFC11B) were submitted to in vitro probiotic tests. All were tolerant to bile salts and five of them to artificial gastric juice, and were all sensitive to tetracycline, chloramphenicol, and erythromycin. L. brevis SFC1A and P. acidilactici SFC9A inhibited all tested pathogenic bacteria and showed the broadest in vitro probiotic activity. Thus, they would be recommended as starter cultures for the elaboration of novel fermented meat products and to compose a bank of indigenous bacteria, as well as contribute to preserving Socol microbiota.