Traditional goat's cheese is highly perishable due to its high moisture content and near-neutral pH, making it susceptible to microbial contamination, particularly by Staphylococcus aureus. This study aimed to enhance the microbiological and nutritional quality of traditional goat’s jebn cheese through the application of essential oil (EO) extracted from Lavandula mairei Humbert. EO was extracted from the aerial parts of L. mairei via hydrodistillation using a Clevenger apparatus. Antimicrobial activity against S. aureus CECT 976 was evaluated in vitro using disc diffusion and broth microdilution methods to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). EO was then incorporated into the freshly prepared goat's cheese inoculated with S. aureus, and microbiological and physicochemical analyses were performed over the storage period. The MIC and MBC of L. mairei EO against S. aureus were determined to be 1.25 mg/mL and 2.5 mg/mL, respectively, indicating a bactericidal effect, with an MBC/MIC ratio of 2 based on values in mg/mL. In treated cheese samples, EO at 0.6% significantly reduced S. aureus counts compared to untreated controls. Furthermore, physicochemical analysis showed a gradual decline in acidity during storage, without compromising the sensory or nutritional properties of the cheese. L. mairei EO exhibits strong antimicrobial properties and holds promise as a natural preservative for enhancing the safety and shelf life of traditional goat's cheese. This plant-based biopreservation method aligns with consumer demand for additive-free, microbiologically safe dairy products.

The natural extracts derived from Pine (Pinus halepensis, region Attica, Greece) needles, male cones, and pollen mixed with male cones, were prepared following a green procedure at all stages, using environmentally friendly methods and safe solvents. Seventeen bacterial strains, relevant to agriculture and food, were cultured under optimal conditions. Antibacterial activity was assessed using agar well diffusion to determine inhibition zones followed by broth microdilution method to determine the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs). The highest inhibition zones were observed for pollen mixed with male cones extract against Listeria monocytogenes, while the lowest MIC values were recorded for pine needles extract against Staphylococcus aureus (7.50 ng/mL). The lowest MBC values were observed from the pollen mixed with male cones extract (0.35 mg/mL) against Bacillus cereus. Notably, the pine needles extract was showed antibacterial activity with MIC and MBC values ranging from 7.50 ng/mL - 7.69 mg/mL and 0.48 – 30.75 mg/mL, respectively against Escherichia coli, Vibrio harveyii, Staphylococcus epidermidis, S. aureus, L. monocytogenes, B. cereus, and Agrobacterium tumefaciens. Significant antibacterial activity was recorded for the pine male cones with pollen extract with MIC and MBC values ranging from 0.02 - 22.4 mg/mL and 0.35 – 22.4 mg/mL, respectively against S. aureus, L. monocytogenes, and B. cereus. The pine male cones extract inhibited B. cereus, L. monocytogenes, and S. aureus with MIC values ranging from 3.6 -14 mg/mL, though MBC values were not detected. The extracts show minimal antimicrobial activity against Pseudomonas aeruginosa, Serratia marcescens, Yersinia enterocolitica, Klebsiella aerogenes, Salmonella enterica, and Salmonella typhimurium. Notably, Citrobacter freundii, Klebsiella oxytoca, Serratia liquefaciens, and Citrobacter sakazakii exhibited resistance to all tested extracts. These findings suggest the potential of natural extracts, especially those from pine needles, as antimicrobial agents in the agricultural and food sectors.

The growing consumer demand for more natural food products has driven the development of clean label alternatives that exclude synthetic preservatives. In this context, natural preservatives have gained attention as potential substitutes for synthetic preservatives traditionally used in the food industry. Fruit fillings, widely used in bakery and pastry products, are characterized by low acidity, low water activity, and high sugar content, making them particularly susceptible to fungal contamination. Among the most used synthetic preservatives are sorbic acid and its salt, potassium sorbate, whose replacement represents both a technological and safety challenge.

The objective of this study was to evaluate the efficacy of a group of berry extract and tapioca starch rich in sorbic acid, applied at two concentrations (0.5% and 1%), as a preservative in an industrially produced banana filling. The product’s stability was assessed over 70 days of storage at 22 °C and 62% relative humidity and compared with a control sample preserved with potassium sorbate.

Microbiological analyses (total viable counts, molds and yeasts, aerobic and anaerobic spore-forming bacilli) were performed, along with physicochemical and rheological tests.

Results showed that both concentrations of the natural extract effectively controlled microbial growth while maintaining the physicochemical and rheological properties of the product throughout the storage period. These findings suggest that natural preservatives could be a viable alternative to synthetic preservatives in bakery products, contributing to the development of more sustainable foods aligned with current consumer expectations.

Ensuring microbiological safety is a growing concern in modern food technology, especially in response to consumer demand for minimally processed fruits and vegetables. In this study, two novel photosensitizer conjugates were synthesized by covalently linking protoporphyrin IX (PPIX) and its Zn (II) complex (ZnPPIX) to polyethyleneimine (PEI). The aim was to develop naturally derived polymeric materials capable of reducing microbial contamination on food surfaces through photodynamic inactivation (PDI) of pathogens. The conjugates were characterized by means of FT-IR spectroscopy, confirming successful covalent binding. Spectroscopic analysis indicated that the porphyrin chromophores retained their optical properties upon conjugation with PEI. Both PEI–PPIX and PEI–ZnPPIX were able to generate singlet oxygen (Φ_Δ = 0.20 and 0.47, respectively) and superoxide anion radicals in the presence of NADH. In addition, the conjugates efficiently photooxidized the amino acid L-tryptophan, a commonly used substrate in biological photochemistry. PDI assays demonstrated strong antimicrobial activity against Staphylococcus aureus, with both conjugates achieving >7 log reductions in bacterial viability. Furthermore, cucumber surfaces were used as a representative raw food commonly found in salads. After microbial contamination, both photosensitizers showed effective pathogen eradication at low concentrations (0.1–2.5 nmol). These results indicate that PEI–PPIX and PEI–ZnPPIX are promising antimicrobial materials with potential applications in the preservation of fresh food and extending shelf life.

Persister cells are a sub-population of growth-arrested bacteria with the ability to transiently tolerate bactericidal levels of antimicrobial agents. Listeria monocytogenes is known to form persister cells upon exposure to high concentrations of these agents and later restore to an active, growing state under favorable conditions. This capability is thought to be a key factor in the survival of foodborne pathogens, such as L. monocytogenes, in food and feed production environments. Therefore, this study aimed to investigate the formation of persister cells in two L. monocytogenes strains isolated from a dairy food production environment. Both strains were exposed to high concentrations of gentamicin and nisin for 2, 4, and 6 hours. The results revealed a biphasic killing curve for both strains, a fundamental characteristic of persister cells. According to our results, a reduction of at least 2 Log(CFU/mL) was observed under most tested conditions. After 6 hours, all conditions stabilized at 8 Log(CFU/mL) or below. These findings demonstrate that L. monocytogenes persister cells can be successfully isolated upon exposure to both gentamicin and nisin. This methodology can potentially be used to isolate and further study L. monocytogenes persister cells, contributing to a better understanding of the adaptive phenotypic traits that may enable certain strains to persist in industrial settings.

Coffee fermentation is a crucial step that significantly influences the final taste and quality of the product. This study investigates the effect of varying wet fermentation durations (0, 12, 24, 36, and 48 hours) on blends of Coffea canephora and Coffea arabica beans. A starter culture of lactic acid bacteria (LAB) was used to enhance fermentation, consisting 2% of Lactiplantibacillus plantarum, Leuconostoc pseudomesenteroides, and Weisella sp., with a consistent Arabica-to-Robusta ratio applied across treatments. Fermentation was carried out at room temperature in a controlled wet environment. After each fermentation period, the beans were dried, roasted, and ground before sensory evaluation. The experiment was conducted in two replicates, and two panelists were involved in the sensory evaluation using the Specialty Coffee Association of America (SCAA) cupping protocol. Panelists assessed aroma, flavor, aftertaste, acidity, body, balance, sweetness, clean cup, overall quality, and final score. Based on the results of the analysis of variance (ANOVA) with a significance value of 0.00, there was a statistically significant effect between treatments (p < 0.05), indicating differences in fermentation and blending times. Fermentation duration had a noticeable impact on sensory attributes. The 48-hour fermentation yielded the highest cupping score, marked by improved acidity, sweetness, and balance, resulting in a cleaner and more complex cup. In contrast, the 12-hour fermentation period showed less flavor development and acidity. In conclusion, controlled wet fermentation with LAB inoculation can enhance the sensory quality of Arabica-Robusta coffee blends. A 48-hour fermentation period was determined to be optimal for producing a balanced, high-quality cup. These findings highlight the potential of microbial starter cultures in improving consistency and flavor development in blended coffee products.

Recent research focuses on developing GABA (γ-aminobutyric acid)-producing psychobiotic strains that can positively influence mental health by modulating the gut–brain axis (GBA) through restoration of stress-induced gut dysbiosis and inflammation. This study evaluated the GABA-producing strain Limosilactobacillus fermentum PB02, isolated from traditional Indian fermented foods, for its activity against lipopolysaccharide (LPS)- and glucose-induced oxidative stress, as well as glutamate-induced toxicity in SH-SY5Y neuronal cell lines. The de Man, Rogosa, and Sharpe (MRS) medium supplemented with 2% monosodium glutamate (MSG) at 37 °C for 72 hours was identified as the optimal condition for GABA production, confirmed using ¹H Nuclear Magnetic Resonance (NMR) and mass spectrometric analyses. The metabolites produced included GABA, along with other important precursors of neurotransmitters such as phenylalanine and L-tyrosine. The strain exhibited key desirable probiotic properties, including non-haemolytic activity, acidic pH tolerance, high bile tolerance (up to 1% bile salts), adhesion to hydrocarbons, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. The cell-free supernatant (CFS) of the isolate provided 79.2 ± 4.87% protection against LPS, 70.1 ± 2.77% protection against glucose-induced stress, and 84.47 ± 3.86% protection against glutamate-induced toxicity in the SH-SY5Y neural cell line model, validated by means of Live/Dead cell imaging. The IC₅₀ values for LPS and high glucose were 200 mM and 1.5 μg/mL, respectively. The strain Limosilactobacillus fermentum PB02 (GenBank accession number PQ555695) has the potential to reduce glutamate toxicity by increasing GABA levels, modulating GABAergic signalling, and influencing the GBA. Our findings suggest that this strain offers moderate-to-high neuroprotection and could be explored further as a potential psychobiotic after evaluation in a depression-induced animal model.

The microbial community present on the surface of grape berries plays a key role in the initial stages of wine fermentation, affecting both the microbiological stability and sensory characteristics of the final product. This study investigated the effects of particle film applications, specifically kaolin and potassium silicate, on the indigenous yeast communities associated with two key grape varieties, “Touriga Nacional” and “Touriga Franca”, cultivated in Portugal’s Douro region. Grape bunches were harvested from a commercial vineyard, where selected rows of “Touriga Nacional” and “Touriga Franca” had been treated at veraison with kaolin (5%) or potassium silicate (at 0.05% or 0.1%). Untreated vines served as controls. To assess the yeast populations, berry samples were washed in isotonic peptone water, and the resulting suspensions were plated on YPD agar. Yeast colonies were isolated, quantified, and identified through molecular analysis of the D1/D2 domain of the 26S rRNA gene. Total yeast count ranged from 10³ to 10⁴ CFU/berry. Overall, the “Touriga Franca” variety presented significantly higher populations of both Saccharomyces and non-Saccharomyces yeasts. However, within this variety, grape samples treated with potassium silicate (at both concentrations) presented the lowest yeast counts. Thirteen yeast species were identified, belonging to the phyla Ascomycota and Basidiomycota. Untreated grapes exhibited significantly higher species richness and diversity compared to treated grapes. Aureobasidium pullulans was the dominant species across all treatments, although its relative frequency varied according to treatment type and grape variety. Multivariate analyses revealed distinct yeast community structures shaped by grape variety, treatment, and their interaction. These findings suggest that particle film applications can change the indigenous yeast community on grape surfaces, potentially affecting fermentation dynamics and wine quality.

Introduction: Bifidobacteria are typical commensals in the gut of various hosts. Raw milk and its products are also sources of bifidobacteria, which is attributable to secondary contamination. The aims of our work were to quantify and identify bifidobacteria in raw milk from various farms and ruminant hosts to detect their species variability, and based on their typical occurrence and taxonomy, to evaluate the possible origin.

Methods: Bifidobacteria were quantified and isolated using bifidobacterial mupirocin media under anaerobic/microaerobic conditions, at 37 °C/room temperature. Colony identification was performed using MALDI-TOF MS and 16S rRNA gene sequencing. TBX medium was used to detect Escherichia coli and other coliforms (aerobically, at 37 °C), which was intended to serve as a control for fecal contamination.

Results: Bifidobacterium crudilactis and B. animalis subsp. lactis were repeatedly detected in raw milk using anaerobic cultivation at 37 °C. Other cultivation conditions reduced bifidobacterial capture and allowed the growth of a larger number of other microorganisms. Also, other bifidobacterial species typical of ruminants were detected in some samples. The detection of β-glucuronidase-positive E. coli on TBX agar was quite frequent; however, it did not fully correspond with the occurrence of bifidobacteria.

Conclusions: B. animalis subsp. lactis is a well-known probiotic species used in dairy production, as well as a multi-host species typical of the gut microbiota. By contrast, the occurrence of B. crudilactis has not yet been confirmed in the gut microbiota, which, together with our results, indicates its environmental characteristic. However, future strain physiological characterization is needed.

Acknowledgements: This work was supported by the METROFOOD-CZ research infrastructure project (MEYS Grant No: LM2023064) including access to its facilities.

Cheese is a popular food in Brazil, but its microbiological safety can be compromised by the presence of potentially pathogenic microorganisms, such as coagulase-positive Staphylococcus (CPS) and Listeria monocytogenes. However, there is a lack of published data on the microbiological quality of cheeses produced in the Metropolitan Region of Curitiba (MRC), which limits the understanding of regional risks to public health and the development of specific food safety strategies. This study seeks to fill this gap by providing unpublished data on microbial counts and fermentation quality in locally produced cheeses. Lactic acid bacteria (LAB) are important for fermentation, helping to develop flavor and inhibit the growth of pathogens. However, the lack of sanitary control in production can result in contamination. There are no reports on the microbiological conditions of cheeses produced in the MRC, so this study aimed to quantify LAB and CPS, as well as to investigate the presence of L. monocytogenes in cheeses from the MRC, in addition to evaluating pH, an important parameter for product safety and quality. Five cheese samples were collected from two cheese factories in the MRC, totaling 10 samples. In the microbiological analysis, CPS were detected at levels above those permitted in the samples from cheese factory 1, indicating shortcomings in the hygiene and health conditions. No CPS (≤1.0 x 10² CFU/g) were detected in cheese factory 2. L. monocytogenes was not detected in any of the samples evaluated. On the other hand, the LAB count was satisfactory in both cheesemakers, suggesting good fermentation. The pH of the samples varied between 4.8 and 5.1 atCheese Factory 1, indicating efficient fermentation, while at Cheese Factory 2, the higher pH (6.57–6.67) suggests problems in the fermentation process. These results highlight the importance of hygienic control and fermentation for the safety and quality of the cheeses.