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Magnetic separation presents significant potential for culture-independent detection of foodborne pathogens in food samples. In this study, we compared two magnetic separation pretreatment strategies for molecular detection using (q)PCR assays targeting Staphylococcus aureus in milk as models. The first approach employed amino-modified silica magnetic particles (ASMPs) for DNA separation, while the second utilized pig IgG-labeled magnetic beads (IgG-MBs) for cell separation. In the ASMPs-based DNA separation strategy, a sensitivity of 36 CFU/mL was achieved when ASMPs-DNA complexes were employed as templates for PCR analysis. To mitigate noise signals originating from ASMPs during qPCR, DNA on the surface of ASMPs was replaced with dNTP, resulting in a sensitivity of 1.6 × 103 CFU/mL. The IgG-MBs-based cell separation approach yielded sensitivities of 3.6 × 104 CFU/mL for PCR and 1.6 × 103 CFU/mL for qPCR following DNA isolation from the bacteria-IgG-MBs complexes. Both methods exhibited exceptional specificity and robustness against background bacteria interference. However, neither approach effectively discriminated between live and dead bacteria. In comparison, the ASMPs-based DNA separation strategy exhibited superior potential especially when ASMPs do not influence the detection system. This research contributes to the optimization of magnetic separation pretreatment strategies for the molecular detection of foodborne pathogens, highlighting the potential of culture-independent detection methods. • We compared two magnetic separation pretreatment methods for molecular detection. • We used (q)PCR assays targeting Staphylococcus aureus in milk as models. • ASMNPs-based strategy has a greater potential for detecting low levels of bacteria. • DNA could be desorbed from ASMPs by dNTP replacement in some critical reactions. [ABSTRACT FROM AUTHOR]

Microplastics have the ability to selectively accumulate microorganisms from their surrounding environments, leading to the formation of biofilms. The potential for microplastic biofilm in food processing environments to contaminate the processing environment and food matrices poses a threat to food safety. This study validated the biofilm formation of three commonly encountered foodborne pathogens, Salmonella enterica serovar Typhimurium (ST), Staphylococcus aureus (SA) , and Listeria monocytogenes (LM) on microplastics, and investigated their tolerance to disinfectant and gastrointestinal tract. Three strains showed distinct biofilm formation patterns, with biomass reaching a steady state at 2 d. Meanwhile, the particle size of microplastics exhibited a specific impact on biofilm formation, with smaller microplastics sizes leading to increased biofilm formation. Sodium hypochlorite (NaClO) can effectively eliminate most biofilm-forming bacteria, except for ST. After treatment with 50 ppm NaClO, 34% cells in ST biofilm survived. Only SA survived in simulated gastric fluid, with around 3 log reduction after 1 h. ST and LM were not detected. All three strains showed a slight increase after treatment with simulated intestinal fluid for 6 h. These results highlighted the capacity of microplastics to transport pathogens through biofilms, emphasizing the potential synergistic effects between microplastics and pathogens in food-associated environments. The biofilm formation of Salmonella Typhimurium, Staphylococcus aureus , and Listeria monocytogenes on microplastics and their tolerance to disinfectant and gastrointestinal tract were investigated. [Display omitted] • All tested pathogens can attach and form biofilm on polyethylene microplastics. • Salmonella Typhimurium biofilm survive under 50 ppm sodium hypochlorite treatment. • Staphylococcus aureus biofilm can survive in simulated gastric juice for over 1 h. [ABSTRACT FROM AUTHOR]

Lactococcus lactis undergoing aerobic respiration can consume oxygen and form an anaerobic environment. Salmonella , as a facultative anaerobic foodborne pathogen, multiply better under aerobic conditions. The purpose of this study was to explore aerobic respiration of Lactococcus lactis subsp. lactis (L. lactis) KLDS 4.0325 inhibitory effect on Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium) SL 1344 in vitro and its colonization ability in vivo. Results indicate that L. lactis KLDS 4.0325 could inhibit the growth of S. Typhimurium SL1344 by producing bacteriocin. And L. lactis KLDS 4.0325 undergoing aerobic respiration could enhance this inhibitory effect, while reducing the expression levels of virulence genes sipB , sipC , and sopE2 in S. Typhimurium SL1344. L. lactis KLDS 4.0325 could be successfully labeled by CFDA-SE fluorescent probe, and the labeling rate was more than 97%. Murine experiments showed that L. lactis KLDS 4.0325 could adhere and colonize in the cecum and colon. Thus, L. lactis KLDS 4.0325 is a promising probiotic strain for the potential inhibition of Salmonella infection via its oxygen-scavenging in host gut. • L. lactis KLDS 4.0325 inhibited the growth of S. Typhimurium SL1344 by producing bacteriocin. • Aerobic respiration enhanced the inhibition effect of L. lactis KLDS 4.0325 on S. Typhimurium SL1344. • L. lactis KLDS 4.0325 reduced virulence genes expression of S. Typhimurium SL1344. • L. lactis KLDS 4.0325 adhered and colonized well in host's cecum and colon. [ABSTRACT FROM AUTHOR]

The invisible foodborne pathogens on strawberry surface endanger its food safety. Therefore, detecting and controlling the foodborne pathogens are crucial for food safety of strawberry. This study comprehensively detected and compared their surface bacterial communities under different packaging films (polyethylene film, gelatin film, and gelatin composite film) through high-throughput sequencing. Compared with fresh strawberries, the dominant bacterial genus of strawberries packaged with different films changed from Rosenbergiella to Acinetobacter after storage. However, few foodborne pathogens and spoilage-related bacteria were found in gelatin composite film-packaged strawberries (S-CG), while harmful bacterial genus of Pantoea and Erwinia were detected with high relative abundances in other films-packaged strawberries. Furthermore, the predication analysis of phenotype and metabolism indicated that Pantoea and Erwinia were the main biofilm-forming and stress-resistance bacteria, which increased potential pathogenic. Fortunately, gelatin composite film maintained the relative abundance of pathogenic bacteria on S-CG surface at a low level. Therefore, this work contributed to evaluating the pathogenic of bacteria community on strawberries during storage and providing a theoretical foundation for active packaging film to control surface pathogenic bacteria of strawberries. • Active packaging decreased the relative abundance of Pantoea and Erwinia. • Pantoea and Erwinia were the main biofilm-forming and pathogenic bacteria. • Most bacteria on strawberry surface exhibited positive correlation with each other. • Active packaging effectively decreased the pathogenic of bacterial community. [ABSTRACT FROM AUTHOR]

Widespread foodborne pathogen Listeria monocytogenes exhibits a pronounced fatality rate among individuals with compromised immune systems, the elderly, and pregnant women. A simple and user-friendly approach is required to identify L. monocytogenes. A distinctive thermostatic nucleic acid amplification technology called polymerase spiral reaction (PSR) has been extensively employed in the identification of foodborne pathogens. In the study, a straightforward and intuitive approach for identifying L. monocytogenes in fresh-cut fruit was established using PSR in conjunction with hydroxy naphthol blue (HNB). Following optimization, the system's primary constitutes-betaine, dNTP, and MgSO 4 were found to be 0.5 M, 1.0 mM, and 6 mM, respectively. Six strains of non- L. monocytogenes were used to test the assay's specificity. The PSR assay performed at 65 °C for 50 min demonstrated the capability to detect L. monocytogenes at level as low as 1 × 10−4 ng/μL DNA per tube and 5.1 × 101 CFU/g of freshly cut fruit. Notably, the sensitivity of this approach surpassed that of PCR by10-fold (1 × 10−3 ng/μL). In order to detect L. monocytogenes , the PSR assay was designed to be rapid, accurate, effective, and apparatus free. This innovative assay has provided researchers a fresh perspective on identification harmful microorganisms. [Display omitted] • A novel method of PSR for detecting L. monocytogenes was established. • The detection limit of L. monocytogenes was 1 × 10−4 ng/μL in pure DNA. • This assay could identify L. monocytogenes at 5.1 × 101 CFU/g of freshly cut fruit. • The sensitivity was 10-fold higher than PCR in pure DNA. [ABSTRACT FROM AUTHOR]

Absorbent food pads are commonly used to absorb exudate drained from food to maintain initial food quality throughout shelf life. However, the absorbed exudate often serves as a nutrient for contaminating pathogens in the pads, requiring appropriate antimicrobial strategies. Here, we developed bacteriophage cocktail-containing absorbent food pads, called phage pads, by impregnating commercial absorbent food pads with a phage cocktail consisting of two Salmonella phages, ФYMFM0293 and ФYMFM0433, followed by air drying for 14 h. The prepared phage pad demonstrated reliable phage titers and water absorbing capacity, and its anti- Salmonella activity was maintained for 84 days under simulated storage conditions. Consistent with the efficient inhibition of in vitro Salmonella growth by the phage cocktail, Salmonella spiked directly on the phage pad at ∼7-log CFU/pad was significantly suppressed for 48 h at 4 °C. When Salmonella -contaminated chicken meat was loaded, Salmonella loads below the detection limit were achieved within the phage pad, in contrast to the control pad, throughout 7 days of refrigerated storage. Considering its stable long-term activity and efficient reduction of specific foodborne pathogens in food exudates, the phage cocktail-containing absorbent food pads could be an effective antibacterial strategy to ensure microbial safety during food distribution to consumers. [Display omitted] • A phage cocktail of ΦYMFM0433 and ΦYMFM0293 efficiently inhibits Salmonella. • A commercial pad soaked with the phage cocktail was dried to prepare a phage pad. • The phage pad has sufficient phage particles and water absorbing capacity. • Anti- Salmonella activity is stably maintained by the phage pad for up to 84 days. • The phage pad effectively controls Salmonella in absorbed chicken exudates. [ABSTRACT FROM AUTHOR]

This study investigates the inactivation kinetics of B. cereus ATCC 14579 (endospores) and E. coli ATCC 25922 when exposed to UV-C light at varying wavelengths (254, 265, 279, and 284 nm). Two scenarios were investigated: stirred liquid suspensions and unstirred static settings (droplets on stainless steel surfaces). The results reveal that the UV-C transmittance through microbial suspensions follows order of 284 > 279> 254 > 265 nm. In stirred conditions, the inactivation kinetics of microbial suspensions exhibited a correlation with the absorption spectra, leading to inactivation kinetic constants order: 265 > 254>279 > 284 nm. However, when focusing on comparative studies of B. cereus inactivation under unstirred conditions, a different order emerged: 265 > 279>284 > 254 nm. Notably, the overall trend revealed that inactivation kinetic constants tend to be higher in unstirred settings, apart from the 254 nm. These variations in inactivation order and kinetic constants can be attributed to enhanced protein damage at wavelengths 265, 279, and 284 nm under unstirred conditions compared to stirred. In summary, we observed effective germicidal efficiency of UV-C light at 265 nm, in both experimental conditions. However, for experimental conditions involving low light transmission through microbial structures such as biofilms, wavelengths of 279 and 284 nm holds considerable promise, ensuring efficient light penetration and enhanced inactivation efficiency. • UV-C light transmittance through microbial suspensions varies (284 > 279>254 > 265 nm). • In stirred suspensions, inactivation kinetics correlated with absorption spectra (265 > 254>279 > 284 nm). • B. cereus inactivation kinetics differed in unstirred conditions (265 > 279>284 > 254 nm), due to enhanced protein damage. • UV-C at 265 nm showed exceptional germicidal efficiency in both scenarios. [ABSTRACT FROM AUTHOR]

Excessive use of traditional food preservatives has raised concerns about their adverse effects. α-Copaene is a natural terpene compound with excellent biological activity; however, the antibacterial activity and mechanism of α-copaene are unclear. Therefore, this study aimed to explore the antibacterial activity and mechanism of action of α-copaene against four common foodborne pathogens: Staphylococcus aureus , Escherichia coli , Bacillus cereus , and Shigella bogdii. α-Copaene inhibited bacterial growth with a minimum inhibitory concentration of 0.5–1 μL/mL and a minimum bactericidal concentration of 2–4 μL/mL. Scanning electron microscopy and flow cytometry showed morphological changes and damage to the cell membrane in cells treated with α-copaene. Confocal microscopy and cell content leakage further confirmed cell membrane damage and increased permeability caused by α-copaene treatment. α-Copaene suppressed biofilm formation by decreasing the hydrophobicity of the cell surface. Furthermore, the hemolytic activity and cytotoxicity assays showed that α-copaene had good biosafety. In conclusion, 4 μL/mL of α-copaene inhibited the growth of S. aureus , E. coli , B. cereus , and Sh. bogdii in beef soup. These results provide evidence of the antibacterial activity and mechanism of α-copaene and pave the way for developing α-copaene as a novel food preservative. • α-Copaene exhibits antibacterial activity and inhibits four foodborne pathogens. • α-Copaene disrupts the cell membrane structure of foodborne pathogens. • Biofilm formation is inhibited via reduced cell surface hydrophobicity. • Hemolytic and cytotoxicity tests indicate satisfactory α-copaene biosafety. • This study paves the way for the development of α-copaene as a novel preservative. [ABSTRACT FROM AUTHOR]

Shiga toxin-producing E. coli (STEC), are among the most frequently reported foodborne pathogens worldwide. They produce two powerful cytotoxins, called Shiga toxins (Stx1 and Stx2). Most DNA-based methods target these genes, and rely on lengthy enrichment protocols which delay early identification of potential threats. Vegetable samples are particularly problematic, as they are rich in components that may inhibit these techniques. In the present study, a short enrichment and improved matrix lysis protocols were combined and tested with qPCR implementing two different detection chemistries, a hydrolysis probe, and an intercalating dye-based one taking advantage of SYBR Green, to determine which performed best. The methodology presented a turnaround time of ∼6 h including the enrichment, sample treatment followed by DNA extraction, and STEC detection with either detection chemistry. Minor differences were identified among both detection chemistries, as the LOD95 were 6.9 and 8.6 CFU/25 g for the probe-based and intercalating dye respectively; both got relative sensitivities, specificities, and accuracies of 100 % and a Cohen's kappa, of 1.00, being this an "almost complete concordance" with the expected result. Overall, same-day detection of STEC in ready-to-eat salad samples, was achieved, and both qPCR detection chemistries demonstrated suitable for the intended application. • Evaluation of the growth of different E. coli serogroups in mTSB with different concentrations of novobiocin was performed. • Decreasing the concentration of novobiocin down to 1–2 mg/L allowed to recover a wider number of serogroups. • An LOD50 of <10 CFU/25 g was reached retaining a relative sensitivity, specificity and accuracy of 100 %. • A Cohen's kappa result of "almost complete concordance", among the multiplex qPCR and culture-based method was obtained. • The method presented a turnaround time of ∼6 h including culture, DNA extraction and multiplex qPCR detection. [ABSTRACT FROM AUTHOR]

Developing novel strategies against foodborne pathogens, like Listeria monocytogenes , is crucial due to their growing resistance to current hurdles and disinfection protocols. Disruption of the cobalamin biosynthesis pathway revealed the importance of vitamin B 12 (B 12) in L. monocytogenes tolerance to cold and copper stress, suggesting that B 12 analogues have potential as hurdles against it on food. In 2021, 10-Br-methyl cobalamin (10-Br-MeCbl) was introduced as an L. monocytogenes antimetabolite. Herein, we re-evaluated 10-Br-MeCbl and tested seven related B 12 analogues against six L. monocytogenes strains and a B 12 auxotrophic Lactobacillus delbrueckii strain. No analogue, including 10-Br-MeCbl, was inhibitory to L. monocytogenes. In contrast, 10-Br-MeCbl, 10-Br-CNCbl, 10-Br-PhCbl, and 10-Br-CNCbl- c -lactam inhibited L. delbrueckii growth (13–27%) at concentrations 50-folds higher than B 12. This inhibitory activity was lost under conditions of B 12 abundance, indicating competitive inhibition. The activity of phenylcobalamin- c -lactam against L. delbrueckii differed compared to a previous study, emphasizing that the antimicrobial activity of B 12 derivatives is not universal and must be examined for each species under the application conditions. Overall, while this study illustrates the potential of B 12 antimetabolites as antimicrobials, it also demonstrates that other classes of B 12 antimetabolites and/or improved strategies are required for tackling pathogens like L. monocytogenes. • Novel strategies are needed to combat foodborne pathogens. • No tested B 12 analogue, including 10-Br-MeCbl, inhibited L. monocytogenes. • Four B 12 analogues inhibited L. delbrueckii at concentrations 50 times that of B 12. • B 12 analogues might act on L. delbrueckii through competitive inhibition. • B 12 analogue inhibitory action is species-based, necessitating specific-validation. [ABSTRACT FROM AUTHOR]

Foodborne pathogens pose a significant risk to human health via the food chain. Here, we evaluated the antibacterial effects of cell-free supernatant (CFS) of Pediococcus acidilactici (P. acidilactici) LWX 401 isolated from food-grade Chinese traditional pickles and found that it exhibited broad antibacterial activity against multidrug-resistant gram-negative Escherichia coli (E. coli) O157:H7 and yogurt-derived gram-positive Staphylococcus aureus (S. aureus), with inhibition zone sizes of 23.10 ± 0.80 and 20.53 ± 0.07 mm, respectively (all P < 0.001 compared with the controls). Moreover, the CFS exhibited strong thermostability and pH tolerance and was capable of inhibiting the formation of biofilms of these foodborne pathogens. Notably, the LWX 401 CFS inhibited both E. coli O157:H7 and S. aureus contamination in milk samples under different storage temperatures (4 °C, 25 °C, and 35 °C), with considerable bacterial reduction by 1–7 log CFU/mL compared with untreated controls. Additionally, the potential antibacterial metabolites (VIP >1, adjusted P < 0.05, and fold-change >2; n = 56) were identified in the LWX 401 CFS by UHPLC-QE-MS metabolomic analysis, and these metabolites were mostly lipids (25.73%) and organic acids (23.30%). Our results provide insights for the development of bio-preservatives against foodborne pathogens in the milk industry. • P. acidilactici LWX 401 was isolated from food-grade traditional Chinese pickles. • LWX 401 CFS showed a broad antimicrobial spectrum against foodborne pathogens. • Pathogenic biofilm formation was inhibited upon LWX 401 CFS treatment. • Antibacterial efficacy was validated in the milk ecosystem. • The potential antibacterial compounds were identified by metabolomic analysis. [ABSTRACT FROM AUTHOR]

Foodborne pathogenic bacteria like, Escherichia coli 0157:H7, Bacillus cereus and Salmonella typhimurium are the biggest threat to food industries. Their growth in the environment and transmission of deadly diseases has become a challenge. The present study confirmed the genetic identity of DD_A7 is similar to the reported probiotic strains of Weissella confusa by analyzing the polymorphism in the conserved region of 16S-rRNA sequence. The Kimchi isolated, non-pathogenic W. confusa DD_A7 strain has shown the potential to control the growth of foodborne pathogens. Furthermore, the cell-free culture supernatant of DD_A7 shows the potential to rapture the membrane integrity of E. coli 0157:H7 by influencing the Ca++ ion channels. The safety concern associated with the usage of DD_A7 strain was also determined by testing its antibiotic susceptibility against different antibiotics and confirmed its non-toxic behavior on mammalian cells. Nevertheless, the strain has also encompassed several applications such as isolation of amylolytic and proteolytic enzymes. Collectively, the study will help to control the growth of foodborne pathogenic bacteria using the studied probiotic strain. In addition, the study will also help to construct a species-specific probe in future for the identification of the non-pathogenic strain of W. confusa for its application in food industries. • Weissella confusa DD_A7 is a non-pathogenic microorganism isolated from Kimchi. • Result of SNP analysis revealed transversion as the most commonly occurred polymorphism. • The CFCS of DD_A7 possess the antibacterial potential against some foodborne pathogens. • DD_A7 has the ability of colonization in the gastrointestinal tract and it is non-toxic for the host. • The strain has the amylolytic and proteolytic activity. [ABSTRACT FROM AUTHOR]

Lactobacillus plantarum YS5, which was isolated from home-made yogurt, demonstrated high percent cholesterol-removal capacity by growing cells (84%) and moderate cholesterol-removal capacity by resting (41.14%) and dead (32.71%) cells. Lactobacillus plantarum ATCC 14917 as a control strain showed moderate cholesterol-removal capability by growing cells (29%), whereas it showed less cholesterol-removal capacity by resting (11.2%) and dead (7.23%) cells. Furthermore, the effect of this strain on serum cholesterol profile of rats is evaluated. Male rats are fed with a high-fat diet supplemented with or without L. plantarum YS5 and normal diet for eight weeks. L. plantarum YS5 supplementation significantly decreased serum total cholesterol, triglyceride, and low-density lipoprotein cholesterol levels, but increased high-density lipoprotein cholesterol. This strain displayed considerable tolerance to acid and bile stress conditions, desirable antagonistic activity against Gram-positive and Gram-negative pathogens, remarkable hydrophobicity, and auto-aggregation. Moreover, L. plantarum YS5 did not represent any side effects, such as hemolytic activity, BSH activity, and antibiotic resistance. The findings of this work indicated that L. plantarum YS5 may be a promising probiotic candidate for application in food industry for production of low-cholesterol products which have hypocholesterolaemic activity in the host. • Lactobacillus plantarum YS5 demonstrated high percent (84%) cholesterol-removal capacity. • L. plantarum YS5 did not represent any hemolytic activity, BSH activity, and antibiotic resistance. • L. plantarum YS5 showed a broad spectrum of antagonistic activity against some important food pathogens. • L. plantarum YS5 could introduce as a promising probiotic candidate for application in food industry. [ABSTRACT FROM AUTHOR]

Antioxidant and antibacterial edible films based on carboxymethyl xylan with licorice essential oil incorporated were successfully developed. The films were prepared by the casting method and characterized using FTIR. The grammage, thickness, contact angle, mechanical and optical properties of the films were measured, together with the evaluation of their antioxidant, antibacterial and anti-biofilm properties against common foodborne pathogens. The FTIR spectra of the films clearly show the successful incorporation of the essential oil. The antioxidant properties of the films linked to scavenging free radicals and lipid peroxidation inhibition were maintained even after a storage period at room temperature (20 days, 25 °C). Moreover, the capacity of these films to inhibit the growth of Enterococcus faecalis and Listeria monocytogenes was demonstrated. The results also suggest the anti-biofilm potential of films incorporated with licorice essential oil. Therefore, these biodegradable films can be used in active packages for food, improving the overall shelf life. • A carboxymethyl xylan-based film incorporating licorice essential oil was developed. • The essential oil was successfully incorporated into the film. • This functional film possesses antioxidant activity. • The film has the capacity to inhibit the growth of foodborne pathogens. [ABSTRACT FROM AUTHOR]

Salmonella is a foodborne pathogen able to adhere and persist on biotic and abiotic surfaces, including vegetables, which are even more linked to foodborne outbreaks. In this work, first we investigated the capability of Salmonella to adhere on different surfaces (stainless steel, polypropylene and lettuce), then we evaluated the potential effect of essential oils in reducing the adhesion and persistence of the pathogen on lettuce. Eight essential oils (EO) were tested on five Salmonella enterica strains (serovars Derby, Thompson, Napoli, Kasenyi and Veneziana). Cinnamomum zeylanicum EO (CEO) was the most effective, according to Minimal Inhibitory Concentration (MIC 1.25–1.87 μL/mL) and to growth/inhibition dynamics. To simulate real conditions, a cocktail of Salmonella Kasenyi, S. Veneziana and S. Napoli was applied on the three surfaces, but it adhered only on lettuce, starting from 1 h of contact (4.59 ± 0.34 Log UFC/cm2). Five μL/mL CEO, applied on lettuce, immediately reduced the loosely and strongly attached cells (reduction of 0.78 Log and 0.63 Log CFU/cm2, respectively), with significant effect up to 120 h. CEO also inhibited the Polyphenol Oxidase activity, thus preserving lettuce colour during storage. Cinnamon EO could therefore help to improve safety and appearance of fresh-cut lettuce during storage. • Salmonella adhesion was tested on three different surfaces (LDs, SSCs, PPCs). • Cinnamomum zeylanicum (CEO) was the most effective essential oil against Salmonella. • CEO reduced strong and loose attachment of Salmonella on lettuce leaves. • CEO reduced Polyphenol Oxidase activity in lettuce, reducing the Browning Index. • CEO could be potentially applied as washing treatments of lettuce. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the antibacterial potential of the Nepeta elymaitica Bornm essential oil (Nepeta EO) against S. aureus and S. Typhi and evaluation its indirect applicability as a natural sanitizer in kohlrabi leaves. GC-MS analysis showed that Nepeta EO mainly contained 1,8-cineol, linalool, E-caryophyllene, and nepetalactone. Based on the results of time-killing assays, disc diffusion tests, and analysis of the released intracellular compounds Nepeta EO was more effective against S. aureus than S. Typhi. Furthermore, scanning electron microscopy images revealed that the cells of both pathogens significantly shriveled and were damaged by Nepeta EO. It is worth mentioning that the indirect application of Nepeta EO (8 mg/mL) in fresh kohlrabi leaves inoculated with pathogens effectively reduced S. aureus and S. Typhi by 4.09 and 5.44 log CFU/g, respectively. Moreover, the Nepeta EO resulted in maintaining the marketable characteristics of kohlrabi leaves, such as texture, color, and stability of chlorophyll content. These results indicated that Nepeta EO has a strong antibacterial ability, which can even indirectly kill both gram-positive and negative bacteria. It has a decent potential to be used as a novel and natural sanitizer in leafy vegetables without altering their quality and organoleptic properties. • 1,8-cineol and linalool were the main phenolic compounds of Nepeta essential oil. • Nepeta essential oil showed a strong antibacterial effect against S. aureus. • Nepeta essential oil reduced S. aureus in kohlrabi leaves by the indirect use. • The chlorophyll content of kohlrabi leaves maintained by Nepeta essential oil. [ABSTRACT FROM AUTHOR]

Fresh fish remain the dominant seafood forms and preservation technologies have enabled them to access ever more distant markets. In this study, we used metabarcoding of the 16S rRNA gene to generate gill microbiomes from Scomber scombrus bought at fishmonger's stores as fresh products but whose labels showed they had been harvested in the Atlantic or Mediterranean FAO fishing areas. Microbial data were analysed with the aim of evaluating their ability to maintain signals from their different geographical origins and the presence of taxa which can potentially act as spoilers, foodborne pathogens, or histamine producers. Results revealed that microbiota, at the end of the wild fish supply chain, had differences related to the two FAO fishing areas (Atlantic vs Mediterranean). Despite the presence of microbial genera potentially associated with spoilage, histamine-production or foodborne pathogens, their patterns confirmed that low-temperature storage is a traditional but effective method of preservation. However, the ongoing spoilage processes were more evident in fresh non-local specimens, dominated by psychrophilic Gram-negative bacteria, whereas fresh local specimens contained Planctomycetes taxa. Therefore, despite the current limitations mainly related to time and cost of the method, our study highlighted that microbiome-based applications are an emergent tool for food system transformation. [Display omitted] • Microbiome-based applications are an emergent tool for food system innovation. • Post-mortem gill microbiomes distinguish geographic origins in fresh fish products. • Health status and post-harvest activities affect microbiomes in fish products. • Additional information on labels can enhance local economies and sustainability. • Microbiome data promote an innovative risk assessment in fish supply chains. [ABSTRACT FROM AUTHOR]

Essential oils of Coriandrum sativum seed (CO) and Cuminum cyminum (CUM) were investigated for their single and combined antimicrobial activities against food-borne pathogens (Streptococcus pyogenes , Listeria monocytogenes , Bacillus subtilis , Enterobacter aerogenes , Salmonella enterica serovar Typhimurium , Shigella dysentery , Aspergillus niger , Saccharomyces cerevisiae and Candida albicans). Also, the AutoDock Vina software and a multi-docking approach was used to investigate the synergistic interactions of ligand combinations on a range of receptors. The results showed the antioxidant activity, total phenolic content (TPC), and total flavonoid content (TFC) of the CUM and CO were equal to 69.52 ± 0.47%, 76.52 ± 0.83 mg GAE/g, 34.5 ± 0.61 mg QE/g, 62.47 ± 0.89%, 44.28 ± 0.66 mg GAE/g, 22.6 ± 0.74 mg QE/g, respectively. The antioxidant activity, TPC and TFC for the combination (CO + CUM) were equal to 76.24 ± 0.31%, 83.60 ± 0.47 mg GAE/g, 36.47 ± 0.52 mg QE/g, respectively. The findings of this study demonstrated that the mixture of CO and CUM essential oils exhibited a synergistic mode for E. aerogenes , and A. niger and an additive mode for L. monocytogenes, B. cereus , S. Typhimurium , S. cerevisiae and C. albicans and no significant effect was observed for S. pyogenes and S. dysentery. According to results, Receptor 5U6M exhibits the highest binding affinity for all ligands, as evident from the most negative docking scores. Conversely, receptor 6NTW demonstrates the lowest binding affinity among the receptors investigated. • Antimicrobial effect of Coriandrum sativum seed (CO) and Cuminum cyminum (CUM) against food-borne pathogenic was evaluated. • Combination of CO and CUM showed synergistic inhibition to Enterobacter aerogenes , and Aspergillus niger. • Synergistic activity between CO and CUM were simulated with multi-ligand molecular docking simulation. [ABSTRACT FROM AUTHOR]

Abstract Campomanesia aurea O. Berg is a native plant of the biome Pampa , which belongs to the family Myrtaceae. The present study aimed to evaluate the antimicrobial and antibiofilme activity of the essential oil of Campomanesia aurea (EOCA) against Listeria monocytogenes ATCC 19114, Staphylococcus aureus ATCC 25923, Salmonella enteritidis ATCC 13076 and Pseudomonas aeruginosa ATCC 27853. An analysis of the chemical composition of the EOCA was realized through gas chromatography coupled to mass spectrometry (GC-MS). The analysis for in vitro evaluation of the antimicrobial and antibiofilm activity was realized by determination of the minimal inhibitory concentration (MIC) and that of the antibiofilm through utilization of 96-well plates with crystal violet, respectively. The action of standard (E) –nerolidol (major compound of the EOCA) was also tested. GC-MS analysis revealed the presence of the sesquiterpene (E)- nerolidol (56.04%) as the main compound in the EOCA. Antimicrobial activity of the EOCA against L. monocytogenes (MIC 5.0 mg mL−1) and S. aureus (MIC 0.7 mg mL−1) was observed. Inhibition of biofilm formation against L. monocytogenes , S. aureus and S. enteritidis could be observed for EOCA and (E)- nerolidol. The results demonstrate that the EOCA was efficient against inhibition of biofilm formation for most of the tested pathogens. Highlights • Essential oil of Campomanesia aurea O. Berg is inhibitor of L. monocytogenes biofilm. • Essential oil of Campomanesia aurea O. Berg can be used against food pathogens. • Essential oil of Campomanesia aurea O. Berg can be a promising source for bioprospection. [ABSTRACT FROM AUTHOR]

Abstract Cronobacter species are opportunistic foodborne pathogens involved in neonatal infections from powdered infant formula (PIF). In this study, a novel saltatory rolling circle amplification (SRCA) method has been developed for detecting Cronobacter spp. in PIF. 16 of Cronobacter spp. strains and 32 of non- Cronobacter strains were examined by using the DNA-directed RNA polymerase subunit beta (rpoB) gene. All Cronobacter strains were identified in pure cultures, whereas no SRCA products were found in non- Cronobacter strains. The detection limits were 3.4 × 102 CFU/mL through observing the white precipitate by naked eye, while 3.4 × 101 CFU/mL by fluorescence visualization. After enrichment, the detection limits of SRCA method in PIF were 8.7 × 100 CFU/g and 8.7 × 10−1 CFU/g by visualization with white precipitate and fluorescence, respectively. Compared with the conventional PCR method, the SRCA has at least 100-fold higher sensitivity and 100-fold lower detection limit. In addition, 85 of PIF samples were investigated for the Cronobacter contamination, and the results were 100% sensitivity, 97.62% specificity and 97.65% accuracy compared with the ISO method. Therefore, the results show that SRCA is a sensitive and visual detection method for the detection of Cronobacter spp. in PIF with great potential. Highlights • A sensitive and visual SRCA method was developed for the detection of Cronobacter in the powdered infant formula. • The SRCA assay was successfully amplified by using a pair of primers in an isothermal condition. • The detection results of SRCA assay were observed by white precipitate or fluorescence with naked eye. • The SRCA method was validated with artificially contaminated powdered infant formula. [ABSTRACT FROM AUTHOR]

Abstract The polyphenol acetates derived from green tea (Camellia sinensis. L) catechins, effectively increases the bioaccessibility as evaluated by simulated invitro enzymatic digestion method. The acetylated polyphenols showed significantly higher bioaccessibility (60.13 ± 0.3%) with respect to their precursors (31.80 ± 0.7%). The antibacterial activity of major catechins and their acetates on food-borne pathogens indicated the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) respectively for gram-positive bacteria (GPB)– Bacillus subtilis (EGCG, 130 μg/mL and 150 μg/mL; EGCG octaacetate 100 μg/mL and 120 μg/mL), Staphylococcus aureus (EGCG, 200 μg/mL and 250 μg/mL; EGCG octaacetate 150 μg/mL and 200 μg/mL) and the gram-negative bacteria (GNB)- Escherichia coli (EGCG, 580 μg/mL and 700 μg/mL; EGCG octaacetate 250 μg/mL and 300 μg/mL) and Yersinia enterocolitica (EGCG, 620 μg/mL and 740 μg/mL; EGCG octaacetate 280 μg/mL and 330 μg/mL). The prepared EGCG octaacetate had higher inhibitory effect against both GNB and GPB, than EGCG, which showed moderate activity on GPB and less effect on GNB. This is attributed to its lipophilic nature, a distinctive property, as evaluated by lipophilicity test. It is further substantiated with membrane permeability assay using fluorescent microscopy and the morphological alterations on E. coli cells by scanning electron microscopy (SEM) studies. Highlights • Enhanced bioaccessibility, membrane permeability of acetylated catechins-first report. • Antibacterial activity of catechins and their acetates on GPB and GNB, food-borne pathogens. • EGCG octaacetate found to be the potential antibacterial compound for GPB and GNB. • Effect of EGCG and EGCG octaacetate on the morphology of E. coli cells by SEM studies. [ABSTRACT FROM AUTHOR]

Abstract In this work we report an eco-friendly and low cost method for reducing and capping silver nanoparticles with a lyophilized extract from grape and orange wastes. The synthesis of silver nanoparticles (AgNPs) was monitored by UV–Vis spectroscopy and their characterization was carried out using Transmission Electron Microscopy (TEM), Diffuse Reflectance Infrared Spectroscopy (DRIFT) and X Ray Diffraction (XRD). The AgNPs were crystalline and spherical, with diameters from 3 to 14 nm and 5–50 nm for the nanoparticles obtained from the grape and orange extract, respectively. DRIFT spectroscopy suggested the involvement of various functional groups from extract secondary metabolites during nanoparticle synthesis and capping nanoparticles. The antimicrobial activity of AgNPs was tested against Escherichia coli O157:H7 and Listeria monocytogenes using the agar diffusion method and optical density (OD 600). Non-significant difference of L. monocytogenes growth inhibition was observed between AgNPs obtained from both extracts, demonstrating a 13.5 mm diameter growth inhibition at 100 μg/ml. For E. coli O157:H7, only the AgNPs obtained from the grape extract exhibited a dose-dependent antimicrobial activity showing a final OD of 0.42 at 100 μL. Highlights • Spherical AgNPs of 10–50 nm were prepared using extracts of orange and grape waste. • Phenolic compounds act as reductor and capping agents for AgNPs synthesis. • AgNPs showed antimicrobial activity against E.coli O157:H7 and L. monocytogenes. • Antimicrobial activity is size particle and concentration dependent. [ABSTRACT FROM AUTHOR]

Abstract This work provides details regarding the physicochemical, antimicrobial and antioxidant properties of poly(vinyl chloride) (PVC)-based films containing 0.4% quercetin and silver nanoparticles (AgNPs) at various concentrations levels. The incorporation of quercetin and AgNPs into the PVC matrix considerably affected the thermal, mechanical and optical properties of the films. Results obtained from the tensile stresgth test, demonstrated an improvement in the mechanical strength of the films after the incorporation of both quercetin and AgNPs. Moreover, an increase in AgNPs concentration increased the rigidity, as compared to control PVC film. Antimicrobial activity against food pathogens (Escherichia coli , Salmonella Typhimurium and Listeria monocytogenes) was evaluated by an antimicrobial barrier test. Results showed that the PVC-based films with quercetin and AgNPs proved to be highly effective to inhibiting bacterial growth. Therefore, these results indicate promising evidence to possibly aid in the prevention of microbial dissemination in foods. Additionally, films incorporated with quercetin and AgNPs expressed an antioxidant capacity when evaluated via the DPPH method. Among all of the films evaluated, the PVC-based films containing 0.4% quercetin and 1% AgNPs were flexible, exhibiting excellent UV-light barrier properties and for use with fatty foods, with the intent of reducing lipid oxidation and preventing food pathogen dissemination. Highlights • The antioxidant and antimicrobial films are suitable for fatty foods. • PVC-based film with AgNPs and Quercetin lead to improvement on mechanical strength. • PVC films showed adequate transparency and significant UV barrier. • Q-AgNPs films were able to reduce the lipid oxidation and bacterial inhibition. [ABSTRACT FROM AUTHOR]

Abstract In the present work, a combined hurdle approach for fermented meat preservation was investigated. Challenge tests were performed in Chorizo sausage model using the maximum allowed NaNO 2 amount (150 mg/kg), a reduced amount (75 mg/kg) and no nitrite, with and without protective cultures inoculation. Cocktail strains of L. monocytogenes and Salmonella spp. were used as indicator strains. In a nitrite reduced sausage model, L. monocytogenes growing trend did not significantly change (p > 0.05) when compared with that containing higher nitrite concentration (150 mg/kg NaNO 2). The addition of L. plantarum PSC20 significantly lowered L. monocytogenes growth when compared with control batches without PCS20 (p < 0.05), obtaining 3.84 log cfu/g and 2.62 log cfu/g lower counts in the batches with 150 mg/kg NaNO 2 and 75 mg/kg NaNO 2 respectively. None of the protective cultures demonstrated in situ antagonistic activity against Salmonella spp. This work pointed out that the reduction of nitrites with the combined use of a protective culture could be a feasible approach to control L. monocytogenes growth in fermented meat foods. Highlights • L. plantarum PCS20 strain is an effective protective culture in fermented meat. • A reduced nitrite amount and a protective culture is a promising hurdle approach. • A complete nitrite elimination may not be effective against all meat pathogens. [ABSTRACT FROM AUTHOR]

Abstract The aim of the present study was to fabricate a stable carvacrol-rich Satureja khuzestanica essential oil (SKEO) nanoemulsion and evaluate its antibacterial activity against food borne pathogens. The effect of determining factors including preparation method, surfactant type, surfactant to oil ratio and hydrophilic lipophilic balance (HLB) were evaluated on the mean particle size and stability of nanoemulsions. The optimized formulation prepared by high speed homogenization method containing 3%w/w EO and 9%w/w surfactant mixture (Tween 80 + Span 80) with HLB value of 10 that produced stable nanoemulsion with mean particle diameter of 95 nm. The defined conditions were applied for fabrication of pure carvacrol nanoemulsion. Both formulations showed appreciable long-term stability. The antibacterial activity of pure SKEO, carvacrol and their nanoemulsions were examined against three food-borne bacteria. The results showed an improvement in antibacterial activity for carvacrol and SKEO nanoemulsions against Salmonella enterica and Staphylococcus aureus. Graphical abstract Image 1 Highlights • SKEO: Satureja khuzestanica essential oil, HLB: hydrophilic lipophilic balance. • Stable nanoemulsions were fabricated from carvacrol and SKEO. • The best surfactants mixture defined as Tween 80: Span 80 with HLB value of 10. • Ostwald ripening was inhibited by optimization of HLB value of surfactants. • The MIC value of nanoemulsions improved 2–4 times compared to the bulk oils in two strains. [ABSTRACT FROM AUTHOR]

Abstract Persimmon tannin (PT), a primary physiological component of young persimmon, exhibits antibacterial activity against several microorganisms, but its effect on methicillin-resistant Staphylococcus aureus (MRSA) remains unclear. In this study, we found that PT from young astringent persimmon fruit had an active inhibition against several MRSA isolated from retail pork and the minimum inhibitory concentrations were 1000 μg/mL. Treatment of PT suppressed cell proliferation, caused decreases in membrane potential and intracellular ATP concentration, destroyed whole cell protein integrity, and induced S phase cell cycle arrest. Electron microscopy demonstrated that PT can change the normal morphology of MRSA and cause severe damage on cell wall and cell membrane. These results indicated that PT presented antimicrobial activity against foodborne MRSA and could be potentially developed as an alternative or supplemental agent to control the spread and infection of MRSA in foods. Highlights • The antimicrobial activity of young persimmon tannin against MRSA was investigated. • Young persimmon tannin showed growth inhibitory effect on MRSA. • Young persimmon tannin induced cell membrane dysfunction. • Young persimmon tannin led to whole cell protein and cell cycle depression. • Young persimmon tannin caused cellular morphology alterations. [ABSTRACT FROM AUTHOR]

Abstract In this study, antimicrobial, anti-quorum sensing and anti-biofilm forming activities of phenolic-enriched extracts produced by enzyme-assisted extraction from oven-dried and lyophilized black grape (Vitis vinifera x (Vitis labrusca x Vitis riparia)), apple (Malus domestica cv. Jonagold) and yellow pitahaya (Hylocereus megalanthus) residues were investigated. Both disk-diffusion and minimal inhibitory concentration (MIC) assays showed increased antimicrobial capacity for many extracts after the carbohydrase treatments. The lowest MIC (12.5 mg/mL) was found for black grape samples against Bacillus cereus and Bacillus subtilis , and for apple and pitahaya samples against Pseudomonas putida. The percent quorum sensing inhibition effect on Chromobacterium violaceum has varied between 9 and 36%, 15 and 24% and 6 and 23% for black grape, apple and pitahaya extracts, respectively, depending on the enzyme treatment. Pseudomonas aeruginosa , P. putida and Staphylococcus aureus biofilms were the most sensitive to the extracts, while the Salmonella enterica , Listeria monocytogenes and Escherichia coli biofilms were modulated by certain enzyme-free and treated samples. The extracts can be good candidates for the development of natural preservatives. Highlights • Carbohydrase-assisted extraction of antimicrobial compounds from fruit residues. • Extracts subjected to antibiofilm and anti-quorum sensing activity assays. • The antimicrobial activity correlated with the total phenolic content of samples. • Phenolic products inhibited the growth and biofilms of food-related bacteria. • Extracts and phenolics suppressed the violacein production in Chromobacterium. [ABSTRACT FROM AUTHOR]

Abstract In many UV sterilization studies, buffer solutions are used for investigating the inactivation mechanisms and evaluating the antimicrobial effect of UV light. The aim of this study was to investigate the effects of the type of buffer solution [phosphate-buffered saline (PBS) or peptone water (PW)] on UV inactivation of major foodborne pathogens, including Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes. A mixed culture cocktail was inoculated in PBS or PW and treated with UV-A, -B, or C irradiation. The bactericidal efficacy in PW was much lower than that in PBS during all UV treatments. In order to trace the cause of the difference, the absorption spectra of the two buffer solutions were analyzed from 190 to 360 nm. The UV absorption pattern of PW was different from those of PBS. The absorbance rate of PBS in the range of UV-A (356 nm), UV-B (307 nm), and UV-C (254 nm) lamp wavelengths was lower than that of PW. As a result, the different UV absorption levels of the two buffer solutions may affect the sterilization efficiency. These results suggest that PBS is the appropriate neutralizing buffer for ensuring reliable data in microbial research treated with UV-rays. Highlights • Antimicrobial effects of UV-A, -B, and C radiations in different type of buffer solutions were investigated. • The bactericidal effects of all UV radiations were lower in peptone water (PW) than those in phosphate-buffered saline (PBS). • The distinction of sterilization efficiency corresponded to different UV absorption levels of PBS and PW. • The selection of neutralizing buffer solution can have a significant effect on UV sterilization. [ABSTRACT FROM AUTHOR]

Abstract This study investigated the combined effects of trans-cinnamaldehyde (TC) and high pressure (HP) to inactivate B. cereus spores in reconstituted infant formula. High pressure (600 MPa for 5 min), with or without TC (0.1%), was applied to reconstituted infant formula with B. cereus spores. Samples were stored at 23 and 7 °C for 4 and 6 weeks, respectively. Microbiological and sensory analyses, pH and emulsion stability of each sample were determined. At 7 °C, B. cereus spores in HP and TC treated formula were reduced by 2.4 and 3.1 log, respectively. At 23 °C, the highest inactivation was observed with TC alone and TC combined with HP, by 2.1 log. Overall, HP showed the highest inactivation rate when combined with TC, confirming the synergistic antimicrobial effect of TC and HP. Remarkable deformation and damage in both B. cereus vegetative cells and spores were observed by transmission electron microscopy after the application of HP and TC. Although TC exhibited a cinnamon-like taste, overall sensory attributes were not significantly different than the control samples. These results suggest that TC and HP could be incorporated in infant formula as a natural intervention to replace the synthetic preservatives and/or enhance the microbiological safety and shelf-life. Graphical abstract Image 1 Highlights • Trans-cinnamaldehyde and HPP has synergistic antimicrobial activity against B. cereus spores in formula. • Trans-cinnamaldehyde and HPP inactivated B. cereus spores by 3.1 log at 7 °C and 14 days of storage. • Trans-cinnamaldehyde and HPP inactivated B. cereus spores by 2.4 log at 23 °C and 7 days of storage. • Trans-cinnamaldehyde and HPP caused notable damage and deformation in internal structures of B. cereus. • Trans-cinnamaldehyde and HPP have potential to be applied in infant formula as a natural preservative. [ABSTRACT FROM AUTHOR]

The scientific and industrial interest in antimicrobial nano-carriers has significantly increased in recent years due to post-processing contamination. Liposomes are considered as promising food-grade carrier systems for bioactive-agents. However, due to relatively low stability of liposomes, surface modification or coating is required to improve its efficiency. The purpose of this study was to fabricate chitosan (CA) stabilized nano-liposomes (chitosomes) to enhance the controlled release and antimicrobial effect of nisin-Z against multidrug resistant (MDR) foodborne pathogens. Chitosome characteristics including encapsulation efficiency (EE %), SEM, thermal stability (TGA, DSC), FTIR analysis, antimicrobial potential and in vitro controlled release were investigated. Overall, chitosomes (CS) were thermally more stable, showed higher EE% (86 ± 1%) as compared to liposomes (56 ± 2%) and controlled S. aureus , E. faecalis and L. monocytogenes growth better than free or liposomal-nisin. SEM confirmed the size of liposomes from 54 to 108 nm, which increased after coating with chitosan. FTIR analysis revealed the interaction between CA and liposomes by merger of amide I and II peaks. Thus, CA-stabilized liposomes not only improve physico-chemical attributes while ensuring sustained release of nisin but also provide a potential approach to control bacterial contamination in food products for enhanced food safety. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effect of sugar content on dielectric properties of chili sauce, and inactivation efficiency when exposed to microwave energy. Heating history showed sugar content was an important factor influencing heating rate when chili sauce was exposed to microwave energy. Also, chili sauce of lower sugar content had a higher dielectric constant and dielectric loss factor. This trend was linked to inactivation efficiency of chili sauce inoculated with foodborne pathogens. As sugar content decreased, the time required to inactivate foodborne pathogen was reduced. Also, the inactivation efficiency of microwave heating was better since conventional heating took much longer to inactivate foodborne pathogens to under the detection limit. Also, our results showed that there was no significant difference in color, except for 25% and 40% sugar content exposed to 915 MHz microwave at 3.0 kW. Even though decreased water activity was observed, there was no significant difference between conventional heating and microwave heating at 1.5 kW and 3.0 kW. These results show not only that microwave heating can inactivate foodborne pathogens without generating significant quality change but also that the effect relies on dielectric properties associated with the sugar content of chili sauce. [ABSTRACT FROM AUTHOR]

Listeria monocytogenes is a foodborne pathogen of public health significance. The most popular pathogen subtypes isolated from food are different from those of clinical isolates. Understanding the behavior of L. monocytogenes along the food chain is important for risk assessment. The objective of this study was to describe the growth and survival characteristics of L. monocytogenes strains and evaluate their association with different subtypes. Food (n = 10) and clinical (n = 4) isolates and one reference strain (ATCC19112) were selected. The growth and survival characteristics of L. monocytogenes was monitored. It showed that the ST5 strains had adaptive capacity in weak acid and alkali, strong resistance to heat stress, violent acid and hypertonic. The serogroup IIb and IIa exhibited the highest acid resistance and bile salt tolerance, respectively. Furthermore, the ST8 and ST9 strains exhibited strong resistance in the bile salt environment and poor growth ability in the low salt broth, respectively. The ST87 food isolate had strong resistance to hypertonic and acid environments. Although further research for more L. monocytogenes strains is needed, the findings of this study should be useful in understanding the growth and survival behavior of L. monocytogenes belonging to different subgroups. • ST5 had adaptability to weak acid & alkali, strong resistance to heat stress, violent acid & hypertonic solution. • ST8 and ST9 exhibited strong resistance in the bile salt and poor growth ability in low salt concentration broth, respectively. • ST87 isolated from food source had strong resistance to hypertonic and low acid environments. [ABSTRACT FROM AUTHOR]

Food safety detection is developing rapidly and with high throughput. Nanoparticles have obvious advantages in foodborne pathogens detection, among which gold nanoparticles (AuNPs) are widely used due to their stable chemical and optical properties. In this study, two kinds of aptasensors based on AuNPs were established. The first one was a visual detection method based on AuNPs lateral flow aptasensor, and the other one was a surface-enhanced Raman spectroscopy (SERS) aptasensor detection based on silver-core gold-shell nanoparticles (Ag@Au). The former allowed for visual readings, eliminated the need for machines, which achieved an initial diagnosis of three common pathogenic bacteria with a detection limit of 20–30 CFU/mL. The sensitivity of the latter can be improved by Ag@Au and the detection limit reached 2 CFU/mL, which can achieve high sensitivity and high-throughput detection. We systematically studied the structure, function and optical signal characteristics of AuNPs in detection, which can provide a favorable reference for the detection of foodborne pathogens in the future. [Display omitted] • The lateral flow aptasensor achieved visual and rapid detection of pathogens. • The Ag@Au SERS aptasensor with high sensitivity provide high through detection. • The multiple application scenario of AuNPs aptasensors is extended. • Rapid testing and batch screening realized by dual mode aptasensors. [ABSTRACT FROM AUTHOR]

Zero-dimensional carbon nanomaterials, known as carbon dots (CDs), have become increasingly popular as nanostructures for food preservation due to their antimicrobial and antioxidant properties. In this study, heteroatom-doped CDs were effectively synthesized from sour whey using a hydrothermal method. The size, chemical, and structural composition, as well as the optical and spectral properties of the synthesized CDs, were thoroughly characterized. Furthermore, this study also investigated the antimicrobial, antioxidant, and cytotoxic properties of CDs. Semi-spherical N- and P-doped CDs with size less than 7.8 nm were synthesized. The results of the cytotoxicity test suggested that CDs are low-toxic nanomaterial. The susceptibility of Salmonella Typhimurium was found to be higher than that of Listeria monocytogenes , with a minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 500 μL/mL and 1000 μL/mL, respectively. Based on SEM observations, it was observed that CDs derived from whey mainly targeted the bacterial cell wall. In the modeling of antimicrobial kinetics, the Weibull model provided a strong fit (R2 > 0.9), particularly for the inactivation kinetics of S. Typhimurium. CDs produced from abundant sour whey, which is a sustainable, inexpensive, and eco-friendly source, exhibited important characteristics such as low cytotoxicity and antimicrobial capabilities. The synthesized CDs have potential as antimicrobial or antioxidant agents in food formulations, as well as UV-blockers and nanofillers in the development of composite polymers for food packaging. • Sour whey were used to synthesize carbon dots. • Carbon dots revealed antimicrobial/antioxidant performance. • Mechanism of antimicrobial activity of carbon dots was demosntated. • Carbon dots were nontoxic on the HCT-116 cell line. • The concept of carbon dots synthesis from whey offered an efficient way to turn waste into nanomaterials. [ABSTRACT FROM AUTHOR]

This study investigated the antifungal effect of curcumin-mediated photodynamic inactivation (PDI) with ascorbic acid (Vc) as a synergist on Penicillium italicum and its biofilms, and evaluated the efficacy in inactivating P. italicum on fresh-cut orange. Results showed that the number of P. italicum spores decreased by 4.61 Log CFU/mL when the concentration of curcumin, Vc and illumination time was 75 μmol/L, 250 mg/L and 20 min, respectively. After PDI treatment, the cell structure of P. italicum was destroyed and leakage of cell contents was observed. Mature P. italicum biofilms were formed after 72 h of incubation, and PDI could reduce the spores in biofilms by 3.23 Log CFU/mL. In addition, under the optimal photodynamic conditions, the number of P. italicum spores in fresh-cut orange decreased by 2.48 Log CFU/g, and the sensory quality was well maintained. In conclusion, curcumin-mediated photodynamic technology could better maintain the freshness of fresh-cut orange. Therefore, this study deepened the understanding of the antimicrobial efficacy of curcumin-mediated PDI on food borne pathogens and its impact on food quality. • Vc was a positive synergist of PDI on P. italicum with curcumin as a photosensitizer. • Curcumin combined with Vc showed better PDI effect on P. italicum and its biofilms. • Curcumin-mediated PDI could better maintain the freshness of fresh-cut orange. [ABSTRACT FROM AUTHOR]

Microbial contamination is the most significant risk associated with consuming minimally processed fresh food products. The processing time of ultrasound (US)-assisted washing generally exceeds 5 min. To reduce the processing time, yet maintain or improve the efficacy of US-free chlorine (FC, 10 ppm) or -peracetic acid (PAA, 80 ppm) (US-FC/PAA), we simultaneously applied ultraviolet C (UV–C) irradiation. Compared with US-FC/PAA (5 min), US-FC/PAA-UV (3 min; 1.71 kJ/m2) treatment of cherry tomato further reduced food-borne pathogens (E. coli O157:H7, non-O157 E. coli , and Salmonella Typhimurium) by 0.45–0.73 log CFU/g and naturally present microbes (aerobic mesophiles, psychrophiles, molds, and yeasts) by 0.28–0.50 log CFU/g. For fresh-cut lettuce, the efficacy achieved using US-FC/PAA-UV did not exceed that using US-FC/PAA, indicating that US-FC/PAA-UV is more effective in reducing contamination on produce with a smoother surface, e.g., cherry tomato. Sensory qualities (color, odor, crispness, and firmness), antioxidant activity, and phenolic, ascorbic acid, lycopene, and chlorophyll content were not affected by any of the treatments. These results suggest that the simultaneous application of US-FC/PAA and UV-C is an effective alternative to US-FC/PAA washing that reduces processing time and thus improves productivity. • UV-C irradiation reduce the processing time of US-assisted washing for cherry tomato and fresh-cut lettuce. • Combination of US-assisted washing with UV-C did not result in quality degradation in cherry tomato and fresh-cut lettuce. • Produce with a smoother surface was more sensitive to US-assisted washing in combination with UV-C [ABSTRACT FROM AUTHOR]

Five Lactobacillus gasseri MA strains originated from human breast milk were investigated for their potential applications in food industry. The antimicrobial activities of MA strains against various human pathogenic microorganisms revealed that the inhibition zones values were in the range of 1.87–14.29 mm for fifteen human food-borne pathogens and 3.25–4.80 mm for two Candida strains. Among L. gasseri strains, the highest antioxidant activity was recorded for MA-5 strain with 54.93% 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and 26.88% ferrous ion chelating activities. The anti-cholesterol abilities of five L. gasseri strains vary from 23.67 to 88.94%. The strains were also evaluated for sensitivity to different nisin concentrations (1.25–150 μg/mL). L. gasseri MA strains with nisin resistance, antimicrobial and antioxidant, anti-cholesterol and lichenase activities are suitable candidates for potential applications in areas such as dietary supplements, making alcoholic beverages and natural food additives as alternative to synthetic preservatives. [ABSTRACT FROM AUTHOR]

The purpose of this study was to inactivate Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes by continuous-type pulsed ohmic heating in buffered peptone water (BPW) and tomato juice. First, BPW inoculated with the three pathogens were treated at different flow rates (0.2–0.4 LPM) and treatment voltages (9.43–12.14 V rms /cm). Both heating rate of BPW and reduction rates of pathogens increased corresponding to decreased flow rate. Accordingly, higher numbers of pathogens survived at a higher flow rate (0.4 LPM). Increasing treatment voltage was an effective way to inactivate pathogens at 0.4 LPM, but the heating rate overly accelerated with increasing voltage adversely affecting food quality. Alternatively, increasing initial temperature by preheating can help inactivate pathogens in the early treatment stage without affecting heating rate. From the BPW experiments, we identified that treatment conditions such as flow rate, voltage, and initial temperature are important factors determining pathogen inactivation performance of continuous-type ohmic heating. When applied to tomato juice, 5 log reductions of all three pathogens were achieved by applying 12.14V rms /cm ohmic heating with 0.2 LPM flow rate after preheating sample to 50 °C with a water bath. Quality aspects of color and lycopene content were observed, and a ∗ and b ∗ values decreased after treatment. Because preheating with additional equipment is inconvenient and occupies valuable space, we developed sequential three cylinder type ohmic heating. By applying the developed sequential ohmic heating, 5 log reductions were achieved for all three pathogens without preheating under the same treatment conditions. Therefore, we concluded that sequential continuous-type ohmic heating can be used utizied effectively to control foodborne pathogens by the juice industry. [ABSTRACT FROM AUTHOR]

Owing to their preservative and antimicrobial effects, essential oils (EOs) are promising natural ingredients for the food industry. The main objective of this study was to investigate the activity of thyme and tea tree oils against selected foodborne pathogens in biofilm mode. The major compounds of these EOs were analyzed by gas chromatography-mass spectrometry (GC-MS) and their antimicrobial activity was determined by a standard broth dilution assay. Biofilms were formed by Escherichia coli O157:H7, Listeria monocytogenes , and Salmonella spp. on abiotic surfaces and were treated with EOs at the minimum inhibitory concentration (MIC) and 0.1% (v/v) for 2 h. Our results demonstrate that EO treatment reduced biofilm cells up to 3.5 log CFU/cm 2 , 2.1 log CFU/cm 2 , and 2.5 log CFU/peg on stainless steel (SS), rubber, and minimum biofilm eradication concentration (MBEC™) surfaces, respectively. Structural changes of the biofilm after exposure to EOs was confirmed by field-emission scanning electron microscopy and viability of biofilm cells was observed using a confocal laser scanning microscope. Overall, these results suggest that EOs could be used to reduce foodborne pathogens in biofilms. [ABSTRACT FROM AUTHOR]

Fresh chicken is a potential source of human infection due to its high microbial load, making the issues regarding its microbiological safety, especially the control of Campylobacter spp., of paramount relevance. Pinosylvin has recently proved effective against this major food pathogen. In this work, we evaluated the efficacy of absorbent pads containing pinosylvin (PS) inclusion complexes (ICs) for the control of fresh chicken meat microbial contamination, focusing on its anti- Campylobacter activity. Coated pads were evaluated in vitro against C. jejuni , followed by in vivo testing in chicken exudates and meat, assessing their anti- Campylobacter activity as well as their efficacy in inhibiting poultry microbiota. Pads exhibited a bactericidal activity in liquid medium at a concentration of 0.08 mg/cm2. At 4 °C, pads with 0.4 mg PS/cm2 exhibited anti- Campylobacter activity in chicken fillets and exudates. Regarding spoilage bacteria, active coated pads were not able to reduce pseudomonads but caused reductions in LAB, psychrotrophs and total viable counts. The present work demonstrates that absorbent pads coated with pinosylvin inclusion complexes possess an efficient antimicrobial activity not only against C. jejuni but also against chicken spoilage bacteria, enabling the use of these active pads to control microbial growth in packaged chicken meat. [ABSTRACT FROM AUTHOR]

Honey is a natural food with functional properties such as antioxidant and antimicrobial activities. These properties vary greatly depending on floral source, climate, and environmental and processing conditions. In this work, we characterized honeys on the basis of their botanical composition and clustered them according to their physicochemical parameters in order to find similarities, and assess their antibacterial action against microorganisms isolated from contaminated food. All honeys studied complied with international quality standards. The data showed differences between multifloral and unifloral honeys in their physicochemical parameters, as well as a direct correlation between colour, phenolic compounds, and antioxidant activity. -Antimicrobial activity resulted from hydrogen peroxide effect. Multifloral honeys with similar phenolic compounds and a botanical composition of eucalyptus and blueweed had greater inhibitory power against E. coli, P. aeruginosa, Salmonella spp., S. aureus and B. cereus . [ABSTRACT FROM AUTHOR]

The swimming crab Portunus trituberculatus is one of the most popular seafoods in South Korea. Despite yearly reports of foodborne illness caused by swimming crab consumption, the microbiota in the whole body of the crab has not been fully characterized. A total of 60 crabs were collected from different sites in the Yellow Sea in the spring and autumn, and the crab microbiota was analyzed by 16S rRNA pyrosequencing. Crab microbial diversity was higher in the autumn than in the spring. Psychrobacter, Vagococcus, Carnobacterium, Lactococcus, and Streptococcus were dominant genera in the spring, whereas Roseovarius and various other genera were dominant in the autumn. The composition of the microbiota differed significantly between spring and autumn (p < 0.01). The relative abundances of potential pathogens, including Lactococcus garvieae, in crabs were higher in spring than in autumn. Thus, the potential risk of foodborne illness by crab intake could be higher in spring than autumn. This study extends our knowledge of potential foodborne illness according to microbiota and may improve the management of crab products. [ABSTRACT FROM AUTHOR]

Numerous dairy products are produced with reduced fat and/or lactose content as consumer demand for foods of modified nutritional content has increased recently. The combined inhibitory effect of milk fat and lactose on the inactivation of E. coli O157:H7, S . Typhimurium, and L. monocytogenes by ohmic heating was investigated in the present study. Response surface methodology with central composite design was used to analyze the inactivation of pathogens and develop a predictive model. Both lactose and fat had an inhibitory effect on the inactivation of all three pathogens by ohmic heating. Inactivation of E. coli O157:H7 has a quadratic relationship with lactose and fat, whereas the cross product of treatment time with fat or lactose has a significant effect on the inactivation of S . Typhimurium and L. monocytogenes . The developed model predicted the inactivation of all three pathogens well within the range of experimental conditions. Color change and lipid oxidation were not observed following ohmic heating, while pH values slightly decreased. Therefore, treatment conditions of ohmic heating should be decided carefully considering the lactose and fat content when using this method to pasteurize milk products. [ABSTRACT FROM AUTHOR]

The present study was aimed at gaining insight into the mode of action of the antagonistic bacteria Pseudomonas graminis CPA-7, which has been previously identified as an effective biocontrol agent against Listeria monocytogenes , Salmonella enterica and Escherichia coli O157:H7 on fresh-cut fruit. In vitro experiments did not reveal any antimicrobial or proteolytic activity on solid media or any biosurfactant activity on hydrophobic surfaces. Metabolites produced by CPA-7 in two different culture media and on 'Galia' melon were unable to inhibit L. monocytogenes populations on 'Galia' melon plugs at 25 °C or 5 °C. In contrast, at 25 °C the population of this pathogen on 'Galia' plugs was reduced by 2.1 and 3.3 log-units when co-inoculated with the antagonist in water, after 24 and 48 h, respectively. CPA-7 did not form biofilms after 72 h at 25 °C (OD = 0.03) or at 30 °C (OD = 0.01) on polystyrene plates and the production of alginate was close to the negative control. Studies of nutritional profiles showed high overlap (NOI > 0.9) between CPA-7 and E. coli O157:H7 regarding the use of carboxylic acids. This functional group could also contain putative targets for competiveness between CPA-7 and S. enterica , although overlapping was not restrictive enough (NOI = 0.83). [ABSTRACT FROM AUTHOR]

The knowledge on the microorganisms present in an industrial process is crucial to delineate the best strategy for their effective control. The aims of the present work were to isolate, identify and characterize (in terms of production of proteases, gelatinases and siderophores, quorum-sensing inhibition and biofilm formation) the resident heterotrophic bacteria present in a minimally processed vegetables (MPV) plant where sodium hypochlorite was used for decontamination. A total of 47 isolates were obtained with 49% belonging to the Pseudomonas genera. Twenty different bacterial species were identified and the conveyor belt in the high care area was found to be a significant source of contamination. Most of the isolates were capable of producing virulence related molecules and all isolates were able to form biofilm. Pseudomonas was the genera with the highest biofilm formation ability, being the predominant microflora along the process chain. Even if no relevant foodborne pathogen was isolated, the results clearly propose that improvements in decontamination during processing are required to effectively control microbial presence in the final product. [ABSTRACT FROM AUTHOR]

The food industry is constantly looking for natural alternatives to chemical additives. Recently, a new red wine pomace seasoning (RWPS) with flavoring, antioxidant, and antimicrobial activities has been obtained from red wine pomace, one of the most important byproduct from winemaking process. This study focused on the antimicrobial activity of a RWPS against three foodborne pathogens: Staphylococcus aureus , Listeria innocua , and Escherichia coli . The microbial growth was assessed in the absence and the presence of RWPS for 34 h at 37 °C. RWPS (40 g L −1 ) presented bactericidal effects against S. aureus and L. innocua . Bacteriostatic effects were observed against E. coli with RWPS at 40 g L −1 and against S. aureus with RWPS at 20 g L −1 . Furthermore, RWPS at 40 g L −1 also slowed the growth of E. coli and L. innocua , extending the duration of the lag phase and decreasing the maximum growth rate of these two microorganisms. In conclusion, the studied seasoning reasonably inhibits the growth of the studied foodborne pathogens. The present study may improve the efficacy of the food chain system by extending the shelf-life of food products and reducing the amount of food wasted. [ABSTRACT FROM AUTHOR]

This study aimed to find out an optimum multiple-strain mixture (MSM) of Lactobacillus with the highest antimicrobial activity (AA) against common food-borne pathogenic bacteria ( Escherichia coli , Salmonella enteritidis , Listeria monocytogenes , and Bacillus cereus ) through mixture design (MD). Hence, Lactobacillus strains were isolated from Iranian traditional fermented olive and pickled garlic, then molecular identified. The results showed that cell-free supernatant (CFS) of the all Lactobacillus isolates had higher AA compared to their microbial suspensions. Therefore, CFS of the Lactobacillus isolates was used to find an optimum proportion through MD. A mixture containing 10% CFS of L. brevis isolated from fermented olive (A*), 80% CFS of L. plantarum isolated from fermented olive (B*), and 10% CFS of L. brevis isolated from pickled garlic (C*) was found as the optimum mixture against common food-borne pathogens. After incubation at 37 °C for 24 h, optical density (OD) of E. coli , S. enteritidis , L. monocytogenes and B. cereus treated with this optimum mixture were 0.131, 0.240, 0.211 and 0.483, respectively. [ABSTRACT FROM AUTHOR]

Sugar beet molasses contains natural components which can significantly inhibit the growth of food-borne pathogens, however, its antimicrobial mechanism has not yet well understood. In the present study, the antibacterial mechanism of sugar beet molasses polyphenols on S. aureus , L. monocytogenes , E. coli and S. typhimurium investigated by SDS-PAGE, SEM and TEM analysis. The sugar beet molasses polyphenols showed bacteriostatic activity against the growth of four food-borne pathogens. Meanwhile, sugar beet molasses polyphenols resulted in leakage of proteins of the four food-borne pathogens cells. Results of SDS-PAGE, SEM and TEM suggested that the antibacterial mechanism may be due to the damaged cytoplasmic membrane and bacterial proteins by sugar beet molasses polyphenols, and the sugar beet molasses polyphenols might change bacterial cells physiology and morphology. [ABSTRACT FROM AUTHOR]

The growth of food-spoilage and foodborne pathogenic bacteria was inhibited by a nisin Z-producing Lactococcus lactis subsp. lactis KT2W2L as determined by the agar spot test and agar well diffusion assay. The growth of Brochothrix thermosphacta DSMZ 20171 T and Staphylococcus aureus CIP 76.25 was inhibited when co-cultivated with L. lactis subsp. lactis KT2W2L whereas the growth of Escherichia coli CIP 76.24 and Salmonella Enteritidis CIP 81.3 was not. However, the growth level of E. coli CIP 76.24 and S . Enteritidis CIP 81.3 co-cultivated with L. lactis subsp. lactis KT2W2L was diminished compared to cultivation without L. lactis subsp. lactis KT2W2L. The neutralized cell-free supernatant (NCFS) collected from the culture of L. lactis subsp. lactis KT2W2L, cultivated with and without indicator strain, exhibited inhibition zones against the indicator strains as determined by the agar well diffusion assay. The results reported in this study indicate that a nisin Z-producing L. lactis subsp. lactis KT2W2L may find application as a bio-preservative for reducing food-spoilage and foodborne pathogens in food products. [ABSTRACT FROM AUTHOR]

Little is known about microbial communities associated with the kimchi manufacturing process. We investigated the structure of microbial communities, focusing on foodborne pathogens, such as Bacillus cereus , enterohemorrhagic Escherichia coli , Clostridium perfringens, Campylobacter jejuni, Staphylococcus aureus, Salmonella spp., Listeria monocytogenes , and Yersinia enterocolitica , during the kimchi manufacturing process, including the brining, washing, and condiment stuffing phases, using culture-dependent and culture-independent analyses. Foodborne pathogens were not identified in any test sample by the culture-dependent analysis, whereas the culture-independent analysis targeting the hypervariable regions V3 and V4 of the 16S rRNA gene detected traces of general or potential foodborne pathogens, such as Campylobacter spp., Enterobacter spp., Escherichia or Shigella spp., Serratia spp., Vibrio spp., Aeromonas spp., Acinetobacter spp., Pseudomonas spp., and Enterococcus spp. However, as the kimchi manufacturing process proceeded, the structure of the microbial community changed, and potential foodborne pathogens were replaced by probiotics, such as lactic acid bacteria. Our results suggest that it may be worth utilizing the culture-independent analysis to complement the culture-dependent analysis for microbiological quality control of the kimchi manufacturing process. [ABSTRACT FROM AUTHOR]