A peptide from black soldier fly larvae, KGNSELEEAKKK, was subjected to structural modifications through cationic and hydrophobic residues. The modified peptide KWWSKLKKFWKK (KK12), which had a net charge of +6 and 41.67

This study evaluated the antiviral efficacy of chlorine dioxide (ClO2) and peracetic acid (PAA) as chemical disinfectants, and UV-C irradiation as a physical treatment, against HAstV-1, applied individually or sequentially on three relevant matrices: oysters, stainless steel (SS; food-contact surface), and low-density polyethylene (LDPE; packaging surface). Infectious viral titers were quantified using a modified immunofluorescence (IF) assay, which was optimized for oyster matrices in this study by adjusting virus adsorption time, antibody conditions, and buffer composition to enhance reproducibility and signal clarity. Treatment with ClO2 (200 ppm, 5 min) and PAA (200 ppm, 1 min) resulted in greater reductions (>2 log10 FFU/mL) on oyster tissues compared to UV-C irradiation (1800 mJ/cm2; 1.8 log10 FFU/mL). HAstV-1 levels dropped below the detection limit when treated with ≥700 ppm ClO2 and ≥1500 ppm PAA on SS and ≥300 ppm ClO2 and ≥900 ppm PAA on LDPE, respectively. UV-C treatment at 3600 mJ/cm2 achieved reductions of 1.37 and 1.63 log10 FFU/mL on SS and LDPE, respectively. Sequential treatments combining ClO2 (50 ppm) or PAA (150 ppm) with subsequent UV-C irradiation (600 mJ/cm2) significantly enhanced HAstV-1 inactivation on oyster surfaces, yielding additional reductions of 0.96 and 0.57 log10 FFU/mL, respectively. Texture and color analyses indicated slight decreases in hardness and chewiness (p < 0.05); however, no significant differences were observed in elasticity or color parameters (p > 0.05). The modified IF assay demonstrated improved reproducibility and signal clarity and was successfully applied for detecting infectious HAstV-1 in oyster matrices.

Cronobacter sakazakii, an opportunistic foodborne pathogen, primarily with the infections that can cause bacteremia, necrotizing enterocolitis, and neonatal meningitis. These pathogens are Gram-negative rods, motile with peritrichous flagella without spore-forming capability, can grow under aerobic and anaerobic conditions, and tolerance to acidic conditions and desiccations stress. Phenyllactic acid (PLA), a phenolic acid with broad-spectrum antibacterial activity, is a promising natural preservative. However, its effects on C. sakazakii biofilms remain unclear. This study evaluated the antibiofilm potential of PLA, a natural antimicrobial metabolite, against C. sakazakii and investigated its effects on cell membrane integrity. First, the minimum inhibitory concentration (MIC) of PLA was assessed at 4 mg/mL. The MIC (4 mg/mL) of PLA was observed to reduce C. sakazakii for planktonic cells and biofilm formation on food-contact surfaces (stainless steel, silicon rubber, and polyvinyl chloride) by about 3 log CFU/cm2, respectively. PLA at 4 mg/mL significantly altered ALP activity, intracellular and extracellular ATP, suggested membrane disruption, cell integrity, and leakage of intracellular components. Fourier-transform infrared spectroscopy (FTIR) analysis provided extracellular polymeric substances composition. As confirmed by confocal laser scanning microscopy and scanning electron microscopy revealed disrupted biofilm architecture and altered cell morphology. Mechanistic analyses demonstrated that PLA exposure increased membrane permeability, indicated by elevated extracellular ATP and protein leakage, while intracellular ATP levels decreased. All things considered, these results clarify PLA's effectiveness against biofilm of C. sakazakii. These results demonstrate that PLA inhibits C. sakazakii biofilm formation primarily by disrupting membrane integrity, suggesting its potential as a natural antimicrobial strategy for controlling biofilms and supports the potential application of PLA as an effective antimicrobial agent in food industry to enhancing food safety.

Lactose intolerance (LI), which affects approximately 75% of the global population, leads to symptoms such as abdominal pain, bloating and diarrhea. The primary management strategy for LI involves the avoidance of lactose-containing products. Although there is no cure for LI of genetic origin, the administration of prebiotics, including the consumption of galactooligosaccharides (GOS) and, potentially, the regular, low-level intake of lactose, may modify the gut microbiota to aid in symptom management. We conducted a six-week, single-blind trial on 14 participants who self-reported LI to examine the effects of GOS vs. low level lactose in the context of a normal diet on the gut microbiota. Fecal samples, gastrointestinal symptom reports and dairy consumption data were collected throughout the study. No significant changes in alpha and beta microbial diversity were observed within the GOS and lactose groups individually. There were significant increases in Actinobacteria (P<0.0001) and Firmicutes (P=0.0006) phyla in the GOS group. Additionally, a considerable elevation in amount of the genus Bifidobacteria (P<0.0001) and a reduction in self-reported diarrhea incidents (P=0.0085) were observed in the GOS group. The findings suggest that GOS enhances the presence of commensal Bifidobacteria and potentially alleviates LI symptoms.

Foodborne pathogens present a significant public health concern where fresh produce is a key agricultural product. Rapid and sensitive detection methods are essential to ensure the safety of such produce. This study aimed to develop and optimize a modified multiplex polymerase chain reaction (mPCR) assay, which incorporates enhancements to conventional PCR, for the simultaneous detection of Escherichia coli, Salmonella, and Listeria monocytogenes in fresh produce. The specificity of each primer pair was validated using 15 strains, confirming 100% accurate detection of pathogenic strains without cross-reactivity. Since no false positives were observed, the assay demonstrated 100% precision, highlighting its reliability in distinguishing target pathogens. The sensitivity of the mPCR assay was demonstrated through serial dilutions, detecting Salmonella down to 10 fg µl-1, L. monocytogenes to 100 fg µl-1, and E. coli to 1 pg µl-1. The mPCR assay was then successfully applied to romaine lettuce and kale, demonstrating its effectiveness in detecting pathogens in mixed samples inoculated at varying concentrations (109-101 CFU ml-1). Kale exhibited greater sensitivity, detecting pathogens at lower levels, while romaine lettuce also provided consistent detection. This study highlights the potential of mPCR for enhancing food safety by providing rapid and sensitive pathogen detection in fresh produce.

Stress-resistant Listeria monocytogenes present serious food safety challenges due to their ability to survive under refrigeration, acidic pH, and high salinity. To enable rapid on-site detection, we developed LM-ResiChip, a portable, microfluidic chip-based qPCR assay targeting stress-resistance-associated genes in L. monocytogenes. Using comparative pangenome analysis of 38 L. monocytogenes genomes, we identified four molecular markers, dasC, malL, gtfA, and thiE, consistently present in resistant strains and functionally linked to salt, oxidative, and nutrient stress adaptation. The assay was implemented on a compact qPCR system with a 3D polymer-based chip, allowing simultaneous duplex detection of all four target genes in a single run. The LM-ResiChip demonstrated high specificity, amplifying only stress-resistant L. monocytogenes (n = 32) and showing no cross-reactivity with stress-sensitive strains or other Listeria species (n = 19). It achieved sensitive detection down to 101 CFU/mL in both pure culture and enoki mushroom samples. All genes exhibited strong linearity (R2 > 0.994) and amplification efficiencies of 90-96 %, confirming robust performance even in complex food matrix. This fielddeployable, cost-effective system offers a powerful solution for real-time detection of stress-resistant L. monocytogenes, enhancing proactive food safety monitoring and risk mitigation in processing environments.

Raw milk microbiota is influenced by farming practices, environmental exposure, and seasonal changes. This study investigated how organic and conventional dairy farming practices influence the microbial composition of raw milk over a 1-yr period. Milk and environmental samples were collected quarterly from 7 dairy farms (4 organic and 3 conventional) in Oregon and analyzed using microbiome sequencing. Across all seasons, the microbial community of raw milk was largely similar between organic and conventional farms, with Escherichia-Shigella being the most abundant genus. Aerobic plate counts were significantly higher in conventional raw milk during winter and summer. Organic milk showed greater seasonal variation in α diversity (Shannon index 1.81 ± 0.40 in winter to 1.01 ± 0.34 in fall), whereas conventional milk remained more stable. No significant β diversity differences were observed between farming types. Shared microbial taxa between raw milk and environmental sources varied by season and farming type, reflecting the influence of confinement and grazing. For example, Romboutsia was more abundant during grazing seasons in organic farms, whereas Clostridium sensu stricto 1 appeared uniquely in conventional milk in winter. These seasonal and housing-related trends highlight how farm management shapes milk microbiota.

This study evaluated the thermal inactivation properties of Aspergillus flavus (A. flavus) and Aspergillus oryzae (A. oryzae) in hazelnut kernels and shells to assess the suitability of using A. oryzae as a surrogate and explored the potential of radiofrequency (RF) dielectric heating to control Aspergillus mold. Both molds exhibited similar heat sensitivities at 45, 55, and 65°C, achieving complete inactivation at 65°C without holding time, though resistance persisted at 45°C even with prolonged heating. Notably, A. flavus was 5°C more heat-resistant and more sensitive to holding time compared with A. oryzae. The critical inactivation temperature was 55°C for A. oryzae and 60°C for A. flavus. At 50°C, A. oryzae displayed comparable thermal resistance in hazelnut shell and kernel powders, but its behavior diverged at 55°C. While A. oryzae reduction was observed in shells during inoculation, no reduction occurred in kernels. RF heating achieved a 0.48-log reduction in A. oryzae in inoculated in-shell hazelnuts when the kernel temperature reached 70°C, increasing to a 0.81-log reduction when the shell temperature reached 65°C. The incomplete inactivation on the shell surface might be attributed to the low moisture content and poor thermal conductivity of the shells. Lipid oxidation of RF-heated kernels was evaluated by fatty acid content and K values, and no significant differences were observed from the unheated samples. These findings highlight the potential of using A. oryzae as a surrogate of A. flavus and RF heating to inactivate Aspergillus to ensure hazelnut safety and prevent lipid deterioration.

The biofilm-mediated persistence of Pseudomonas aeruginosa in the food and biomedical sectors is currently a global concern. In light of this challenge, this study investigated a preventive approach against P. aeruginosa biofilm formation using Flavourzyme, a food-grade peptidase, considering its antibiofilm potential. The results revealed that a co-culture comprising 300 µL/mL (1 × minimum inhibitory concentration [MIC]) of Flavourzyme could kill P. aeruginosa. On the MBEC™ biofilm-forming device, 0.125 × MIC of Flavourzyme inhibited > 4.5 log CFU/peg of biofilm. Cell motilities and the biosynthesis of quorum sensing (QS) molecules such as N-acyl-homoserine lactones (AHLs), including C4-HSL, decreased significantly at 0.06 × MIC of Flavourzyme and became undetectable at 0.125 × MIC. Interestingly, while 0.03 × MIC of Flavourzyme elicited diverse expressions of QS and virulence-regulating genes, ≥ 0.06 × MIC of Flavourzyme remarkably suppressed the relative genomic expressions. This study proposes Flavourzyme as a potent antibiofilm agent against P. aeruginosa biofilms, recommending specific concentrations for effective use in food preservation.

Seafood is essential for achieving the United Nations Sustainable Development Goals (SDGs), particularly in enhancing food security and supporting sustainable livelihoods. However, the seafood industry faces challenges due to the short shelf life of its products, primarily caused by microbial contamination and biofilm formation, which increase resistance to conventional preservation methods. This review examines the microbial hazards associated with seafood, focusing on the complexities of biofilm formation on seafood and processing equipment. It explores advanced non-thermal decontamination technologies, such as electron beam irradiation, cold plasma, and ultrasonication, alongside natural antimicrobial strategies, including plant extracts, biosurfactants, and antimicrobial peptides. These innovative methods show potential for enhancing seafood safety, extending shelf life, and preserving nutritional quality. The review emphasizes the need for ongoing research into effective biofilm control, improved detection methods, and robust regulatory frameworks to ensure the production of safe, high-quality seafood. Additionally, a bibliometric analysis highlights current research trends and key focus areas within this field, providing a comprehensive overview of the evolving scientific landscape related to seafood safety and biofilm management, and identifying critical opportunities for future research and innovation.

Whey protein is commonly used to prevent sarcopenia in older adults due to its high digestibility and amino acid content. Its bioactive components may also influence the gut microbiota, which plays a growing role in healthy aging as microbial composition shifts with age. This study investigated whether daily supplementation with whey protein isolate (WPI) improves gut microbiota diversity and composition in older adults. Sixteen participants consumed 59 g of WPI (35 g of protein) daily for 3 wk. Whey protein isolate significantly increased Simpson diversity in individuals with low baseline diversity, with effects appearing by d 3 and persisting after intervention. Taxonomic analysis revealed increases in beneficial taxa (e.g., Ruminococcaceae, Faecalibacterium, and Christensenella) and reductions in potentially harmful groups (e.g., Proteobacteria, Streptococcaceae, and Colidextribacter), particularly in the low diversity group. Analysis of compositions of microbiomes with bias correction based on absolute abundance confirmed increases in probiotic genera including Lactobacillus, Lactococcus, and Christensenella. Despite these microbial shifts, no significant changes were observed in gastrointestinal symptoms or stool consistency. These findings highlight the potential of WPI supplementation as a dietary strategy to promote a healthier gut microbiome in older adults, particularly in those with low baseline diversity.

The aim of this work was to determine the antibacterial properties and mode of activity of isolated corn gluten meal (CGM) hydrolysate fractions. The P1 fraction from reverse-phase liquid chromatography separation of pepsin-hydrolyzed CGM presented the most potent antibacterial activity with minimum inhibitory concentration (MIC) of 1 mM and 4 mM minimum bactericidal concentration (MBC) against Staphylococcus aureus ATCC29213. The kinetics of P1 antibacterial activity revealed a bacteriostatic effect at 1 x MIC and 2 x MIC for 8 h, but a bactericidal effect at 4 x MIC. The P1 fraction at 1 x MIC and 4 x MIC disrupted the membrane integrity of S. aureus after 8 h exposure as observed by confocal laser scanning microscopy. Scanning electron microscopy and transmission electron microscopy indicated cell surface damage and cytoplasmic leakage in S. aureus after being exposed to the P1 fraction. Synchrotron radiation-Fourier transmission infrared (SR-FTIR) microspectroscopy revealed changes in nucleic acid, protein, and fatty acid compositions of S. aureus cell membrane after 8 h exposure to P1 at 1 x MIC. The antibacterial activity of P1 exhibited stability within the range of pH 4.5-6.5 and temperatures of 40-100 degrees C. The P1 exhibited relatively low hemolytic activity up to 8 mM. The P1 fraction at 8 mM suppressed the growth of S. aureus during a challenge test on commercial ultra-high temperature milk inoculated with S. aureus ATCC29213. Eleven novel hydrophilic peptides (6 cationic and 5 anionic) were identified and the peptide EAGGGEDDKKKVE showed the most potent antibacterial activity. We conclude that the pepsin-hydrolyzed CGM peptide fraction showed potential to be utilized as a novel antimicrobial agent for the control of S. aureus in foods.

Weissella is a fascinating genus that has garnered increasing attention for its probiotic potential and industrial versatility. In this study, we present a detailed genomic and phenotypic investigation of six Weissella strains isolated from kimchi, identified as W. cibaria (254, 256, 258, 260) and W. confusa (255, 257). Genomic analysis revealed species-specific differences, with W. cibaria linked to cell cycle regulation and replication, while W. confusa displayed adaptations for motility and metabolic diversity. Antibiotic resistance gene analysis revealed the presence of daunorubicin resistance (drrA), multidrug resistance determinants (bmr3, lmrA, ykkCD), and species-specific resistance to bicyclomycin (bcr1, bcr2) and quaternary ammonium compounds (qacC). Phenotypic antibiotic susceptibility testing demonstrated intrinsic resistance to vancomycin alongside high sensitivity to ampicillin, erythromycin, chloramphenicol, and gentamicin. Probiotic assessments highlighted significant tolerance to acid, bile salts, and enzymatic stress, with W. cibaria 256 and W. confusa 255 showing superior survivability under simulated gastrointestinal conditions. High surface hydrophobicity observed in W. confusa 255 and 257 further underscores their adhesion capabilities, which are crucial for gut colonization. Exopolysaccharide (EPS) production was further characterized by FTIR analysis, revealing diverse functional groups associated with structural protection and probiotic functionality. Morphological characteristics as determined by field emission scanning electron microscopy (FE-SEM) revealed rod-shaped cells of 1.39-1.87 μm in length and 0.50-0.70 μm in width for W. cibaria strains versus 1.02-1.45 μm in length and 0.54-0.62 μm in width for W. confusa strains. These findings provide novel insights into the genomic and phenotypic underpinnings of Weissella species' probiotic properties, resistance mechanisms, and adaptability to fermented food environments, highlighting their promising applications in functional food development and human health enhancement.

Listeria monocytogenes (Lm) can persist in stressful conditions such as low pH, temperature, and salt concentration. Omics approaches enable the investigation of biomolecular features at both the transcript and protein levels. This study aimed to understand stress response mechanisms by analyzing transcript and protein levels of stress-resistant L. monocytogenes (SR-Lm) under multiple stress conditions. RNA sequencing was performed at 4, 8, 12, 24, and 48 h growth under a multiple stress condition (pH 3 + 1 °C + 5% salt) and RT-qPCR was also conducted. Gene expression analysis revealed upregulation of the yebS, tsx, secA, gap, gtfA, along with several stress-related genes (cspB, cspD, spxA, and cysK) during 48 h. Protein expression profiles of SR-Lm were conducted under (1) 5% salt+1 °C, (2) pH 3 + 1 °C, and (3) pH 3 + 1 °C + 5% salt conditions at 4 and 12 h. Some proteins including Gap, Eno, Citz, and PurM were upregulated in both analyses, potentially associated with stress-related biomarkers. KEGG pathway analysis was performed using proteomic data to predict stress response mechanisms including chaperone, glycolysis, and glutamate decarboxylase system (GAD). Cell morphology under stress and normal conditions was observed, with some elongated, thin, and bumpy cell shapes under acid and multiple stress conditions. This study provides new insights into the stress response of SR-Lm, enhancing the understanding of how Lm survives in adverse food processing and storage environments.

The conventional method of antigen-based serotyping for Salmonella poses challenges due to the necessity of utilizing over 150 antisera. More recently, in silico Salmonella serotyping has emerged as a predictive alternative. The purpose of this study was to predict the serovars of 62 Salmonella enterica strains isolated from Korean poultry operations and their genetic characteristics using whole genome sequencing. The analysis employed diverse methods, including ribosomal, and core genome multi-locus sequence typing (MLST), based on Salmonella In Silico Typing Resource (SISTR). Pangenome, clusters of orthologous groups (COG) analysis, and identification of virulence and antibiotic resistance genes were conducted. Salmonella enterica subspecies enterica serovars were observed and clustered based on the pangenome and phylogenetic tree: 21 Salmonella Albany (Albany), 13 Salmonella Bareilly (Bareilly), and 28 Salmonella Mbandaka (Mbandaka). The most frequently observed sequence types for the three serovars were ST292 in Albany, ST203 in Bareilly, and ST413 in Mbandaka. 18 antibiotic resistance genes showed varying presences based on the serovars, including Albany (qacEdelta1, tet(D), CARB-3 (blaCARB-3), and dfrA1) and Bareilly (aac(6')-ly). Intriguingly, a mutated gyrA (Ser83 → Phe, serine to phenylalanine) was observed in all 21 Albany strains, whereas Bareilly and Mbandaka carried the wild-type gyrA. Among 130 virulence genes analyzed, 107 were present in all 62 Salmonella strains, with Mbandaka strains exhibiting a higher prevalence of virulence genes related to fimbrial adherence compared to those of Albany and Bareilly. The study identified distinct genetic characteristics among the three Salmonella serovars using whole genome sequencing. Albany carried a unique mutation in gyrA, occurring in the quinolone resistance-determining region. Additionally, the virulence gene profile of Mbandaka differed from the other serovars, particularly in fimbrial adherence genes. These findings demonstrate the effectiveness of in silico approaches in predicting Salmonella serovars and highlight genetic differences that may inform strategies for antibiotic resistance and virulence control, such as developing rapid diagnostic tools to detect the AMR (e.g. tet (D), and gyrA) or targeting serovar-specific virulence factors like fimbrial adherence genes in Mbandaka to mitigate pathogenicity.

The rising popularity of raw goat milk has heightened concerns about its safety. This study examined how differences in milking and cleaning practices influence the quality and microbiota of goat milk from small-scale Oregon farms during July and August. Milk quality was assessed through somatic cell counts (SCCs) and components, while microbiota was evaluated using viable counts and 16S rRNA sequencing. Sequencing revealed a diverse microbial community, dominated by genera such as Staphylococcus, Escherichia-Shigella, and Pseudomonas, with pathogenic taxa like Salmonella and Campylobacter largely absent or detected at negligible levels. Alpha diversity varied significantly among sample types but not across farms, and beta diversity indicated considerable dissimilarity in microbial composition. Importantly, regression models identified significant associations between hygiene practices and bacterial abundance: the absence of glove use and hand sanitation was linked to increased levels of Escherichia-Shigella, Kocuria, Enterococcus, and Corynebacterium, while the use of bleach-chlorhexidine sanitizer was associated with higher Deinococcus. These findings highlight the role of rigorous hygiene protocols in shaping the microbiota of raw goat milk and emphasize the need for targeted practices to minimize contamination risks.

Lactose intolerance, which affects about 65-75% of the world's population, is caused by a genetic post-weaning deficiency of lactase, the enzyme required to digest the milk sugar lactose, called lactase non-persistence. Symptoms of lactose intolerance include abdominal pain, bloating and diarrhea. Genetic variations, namely lactase persistence, allow some individuals to metabolize lactose effectively post-weaning, a trait thought to be an evolutionary adaptation to dairy consumption. Although lactase non-persistence cannot be altered by diet, prebiotic strategies, including the consumption of galactooligosaccharides (GOSs) and possibly low levels of lactose itself, may shift the microbiome and mitigate symptoms of lactose consumption. This review discusses the etiology of lactose intolerance and the efficacy of prebiotic approaches like GOSs and low-dose lactose in symptom management.

Rotavirus (RV) causes severe gastroenteritis in infants and young children worldwide. Fresh produce has been reported as a source of RV infection during production and harvesting, leading to foodborne illness. Cases of contamination from contact surfaces have also been reported. Therefore, this study applied chemical methods (chlorine dioxide [ClO2], peracetic acid [PAA]), physical methods (gamma irradiation), and a combination of methods (disinfectants + gamma irradiation) to inactivate RV on food contact surfaces (stainless steel) and food (lettuce). Furthermore, the changes in food quality after the combined treatments were assessed. The results of the chemical treatment showed that RV was reduced below the detection limit after treatment for 1 min with 20 ppm ClO2 or 120 ppm PAA in RV suspension. On stainless steel, treatment with 200 ppm ClO2 or 2,000 ppm PAA reduced contaminated RV by more than 4 log. A 5 min treatment with 50 ppm ClO2 or 80 ppm PAA on lettuce reduced the RV by 1.79 and 0.75 log, respectively. Treatment with 4 kGy of gamma irradiation resulted in more than 5 log reduction in suspensions and 3.27 log reduction on food. The sequential treatments, including 30 ppm ClO2 followed by 1.5 kGy gamma irradiation and 80 ppm PAA followed by 1.5 kGy gamma irradiation, showed additional inactivation effects (p < 0.05) compared to each single treatment. No changes in food quality (color difference and texture) were observed after any treatments, suggesting that the combined treatment of both ClO2 and gamma irradiation and PAA and gamma irradiation can be applied in the fresh food industry to reduce RV contamination.