Journal of Food Safety最新文献

This study investigated the effectiveness of plasma-activated water (PAW) and plasma-activated hydrogen peroxide (PAHP) in reducing egg-associated pathogens. The antimicrobial activity of these solutions against Salmonella Enteritidis, Campylobacter jejuni, and Staphylococcus aureus on eggs was evaluated at different plasma treatment durations. The results demonstrated that increasing the duration of plasma treatment enhanced the antimicrobial efficacy of both PAW and PAHP. The bacterial counts of the egg-associated pathogens significantly decreased from 7.61, 7.59, and 7.54 log (CFU/egg) to 5.4 and 3.09, 5.36 and 3.11, and 5.08 and 3.73 log (CFU/egg) for PAW and PAHP, respectively. The characteristics of the plasma solutions, including electrical conductivity, pH, H₂O₂, NO₃¯, and NO₂¯, synergistically acted as antimicrobial agents in both PAW and PAHP treatments. The storage study revealed that PAHP treatment had no adverse effects on the eggs' pH, albumen and yolk color, Haugh unit, and yolk index. However, it did result in reduced eggshell strength and compromised cuticle integrity. Overall, this study demonstrates the successful application of PAW and PAHP in effectively inhibiting egg-associated pathogens while preserving essential egg quality attributes. Further research is needed to optimize the treatment conditions and investigate the long-term effects of PAW and PAHP on eggs in larger-scale applications. This research contributes to developing innovative and sustainable approaches for enhancing the safety and quality of eggs in the food industry.

From 2000 to 2022, all and serious notifications of the EU Rapid Alert System for Food and Feed (RASFF) on herbs and spices were examined to identify the most notified products, their associated hazards and origin countries, as well as the consequent notification classification and actions taken. The data reveals that 3741 notifications were transmitted for herbs and spices during the last 23 years, accounting for 5.3% of the RASFF total notifications of all product categories (70630). Border rejection and serious risk decisions represented 37.9% and 39.5% of the total herbs and spices notifications, respectively. In the last 5 years, serious notifications ranged from 76.6% to 87.2% of all herbs and spices notifications. India was the most notified origin country (23.6%), followed by Brazil (8.7%), Thailand (7.2%), Turkey (5.8%), and China (4.6%). The top 10 notified herbs and spices were chili, black pepper, curry, paprika, nutmeg, spice mix, basil, mint, ginger, and cumin, while the top 10 hazards were Salmonella, aflatoxin, Sudan 1, Sudan 4, ethylene oxide (EtO), ochratoxin A, chlorpyrifos, Escherichia coli, pyrrolizidine alkaloids, and color E 160b. Approximately 96.3% of black pepper, 71% of chili, and almost all nutmeg serious notifications were related to Salmonella, aflatoxins, and mycotoxins, respectively. Strict measures to minimize the risk associated with such contaminants in herbs and spices must be implemented.

There is an increasing demand for plant-based burger patties owing to the health and sustainability issues raised from the consumption of meat. This study aimed to develop plant-based burger patties from pea protein isolates (PPIs) and barnyard millet flour (BMF) through high-moisture extrusion cooking. The extrudates for plant-based burger patties were developed with a blend ratio of 90:10 PPIs:BMF with different screw speeds ranging from 40 to 120 rpm. The extrudates produced with different screw speeds were analyzed, followed by the analysis of the plant-based burger patties. Commercial plant-based burger patties were used as a control. The optimized plant-based burger patties were then stored in aerobic or vacuum packaging for 12 days under refrigerated condition and analyzed. The optimized extrudates produced using screw speed of 80 rpm displayed moderate water absorption index (3.33%), high hardness (4143–4390 g), and high adhesion (0.47 mJ). The plant-based burger patties produced using the optimized extrudates had 2006–2608-g hardness, 0.17 cohesiveness, and 6.70% cooking loss. In comparison to aerobic packaging, the plant-based burger patties stored in vacuum packaging demonstrated lower cooking loss (8.46%), moisture content (18.03%), total color difference (3.02), and total plate count (8.65 log₁₀ cfu/g) after 12 days of refrigerated storage. The protein content of plant-based burger patties was not affected throughout the refrigerated storage. This shows the potential of PPIs and BMF mixtures as meat analogue ingredients and the suitability of vacuum packaging for the storage of plant-based meat.

Fresh apples are vulnerable to Listeria monocytogenes (L. monocytogenes) contamination during handling and storage causing subsequent foodborne outbreaks. Gaseous chlorine dioxide (ClO₂) is an effective antimicrobial agent against L. monocytogenes and could augment food safety. This study investigates the stress and virulence response of L. monocytogenes on apples exposed to a sublethal concentration of ClO₂. L. monocytogenes was inoculated on the surface of apples and exposed to gaseous ClO₂ for 1 h. Gene expression analysis via Real-Time quantitative polymerase chain reaction (RT-qPCR) revealed minimal changes in gene expression compared to control samples. However, a surface-dependent response was observed, with slight upregulation of relevant virulence (hly) and stress (clpC) genes on more hydrophilic surfaces. These findings indicate that gaseous ClO₂ treatment can provide a biostatic effect against L. monocytogenes on fresh produce, shedding light on its antimicrobial mechanism and potential for enhancing apple safety.

Biofilm formation in broiler drinking water systems is a public health concern. Bacterial detachment from the pipes into the drinking water subsequently increases the risk of waterborne transmission and has detrimental effects on animal and human health. The study evaluated the antimicrobial effectiveness of plasma-activated water bubbles (PAWBs) recirculated under different flow regimes against the mixed-species biofilms of Salmonella Typhimurium ATCC13311 and Aeromonas australiensis 03-09 grown on the inner surfaces of polyvinyl chloride (PVC) pipes. A benchtop pipeline model representing broiler drinker lines was developed to compare the biofilm inactivation efficacy of PAWB recirculated at different flow rates, corresponding to Reynold's number of 1000, 2500, and 4000. The synergistic mechanical and oxidative recirculation using PAWB resulted in a higher biofilm inactivation from the pipe walls as compared to recirculation using distilled water alone. Apart from the flow regimes, various parameters including the volume of PAWB circulated, the concentration of the major plasma reactive species, and treatment time affected the susceptibility of the mixed-species biofilms to PAWB treatment. Under all tested conditions, the bacterial cells were below the detection limit of 1 log CFU/mL in water after PAWB treatments. A better understanding of the hydrodynamic variations prevalent in the drinking water system is important for designing an effective disinfection protocol using PAWB. The results obtained from the study provide important information on the use of PAWB for biofilm control strategies.

Low level of rifampicin-resistant E. coli is frequently used in food safety research as a model microorganism and is typically enumerated using traditional Most Probable Number (MPN) method. To simplify the process, we developed and validated a modified MPN method based on lactose peptone broth (LPB) containing rifampicin and bromocresol purple, the broth changes to a yellow color due to pH shifts induced by lactose fermentation from E. coli. E. coli TVS353 were prepared in following suspensions including healthy cells, injured cells, competitive bacteria with or without rifampicin resistance, and unknown natural microflora. E. coli TVS353 was quantified by traditional MPN method and our improved method. At a predicted level of 1 log CFU/mL, there was no significant difference in the MPN index of LPBR compared with TSB and TSBR in these suspensions (p > 0.05). Confirmation results generated from this new color change MPN method were analogous to traditional MPN methods.

Cronobacter sakazakii is a foodborne pathogen predominately transmitted through contaminated dried foods and affects populations including neonates, infants, and the elderly. Following several recent outbreaks, it is now a notifiable infection in those under 12 months of age. Current control methods include strict manufacturing guidelines, with monitoring of this genus a legal requirement in powdered infant formula production. Fatty acids have long been known as antimicrobials, with long-chain fatty acids increasingly identified as agents that target virulence factors. This study gives insight into the changes promoted by three long-chain unsaturated fatty acids (oleic, linoleic, and α-linolenic) on C. sakazakii growth, morphology, and biofilm formation. Each fatty acid was individually introduced to C. sakazakii 29544 both as a sole carbon source and as an addition to complex media. Following comparison to the untreated control, bacterial cells treated with these fatty acids showed a significant and media-dependent impact on growth and biofilm inhibition. With further characterization, long-chain fatty acids, including α-linolenic acid, could be utilized as a control method with minimal safety constraints regarding their use in the food production environment.

The objective of this study was to validate a simulated commercial baking process for traditional crust pepperoni pizza to inactivate Salmonella when contamination was introduced through inoculated flour and pepperoni slices. The unbleached flour and pepperoni slices were inoculated (separate studies) with a 3-serovar Salmonella cocktail and dried back to their respective pre-inoculation water activity level to achieve 6.14 and 6.84 log CFU/g, respectively. The inoculated traditional crust pizza was baked at 260°C (500 °F) for 12 min followed by 15 min of ambient cooling. In both cases, a >6 log CFU/g reduction in Salmonella population was achieved by the first 8 min of baking. The pH (5.23–5.25) and water activity (0.958 ± 0.001–0.938 ± 0.005) of the pizza in this study did not change significantly. The D-values of 3-serovar Salmonella cocktail in traditional crust pepperoni pizza dough were 23.2 ± 1.82, 7.50 ± 0.32, and 2.0 ± 0.15 min at 56°C, 59°C, and 62°C, respectively, with a z-value of 5.7°C. The study validated that traditional crust pepperoni pizzas when baked at 260°C (500 °F) for at least 12 min will reduce Salmonella populations by ≥5 log CFU/g if prebaking contamination occurs via flour and/ or pepperoni.

Mixed crop livestock farming (MCLF) is a growing practice in organic farming where livestock and crops are grown near each other to promote environmental sustainability through recycling. However, MCLF livestock are reservoirs of many zoonotic pathogens, such as Staphylococcus spp., and can serve as sources of cross-contamination for plant food products. A surveillance study was conducted to determine the prevalence and antibiotic-resistance patterns of various Staphylococcus spp. species isolated from the environment of multiple MCLFs and produced from pre-harvest and post-harvest levels within the DC–Maryland metropolitan area. A total of 3038 environmental and pre-harvest produce and 836 post-harvest produce samples were collected from eight farms and two retail supermarkets. In addition, 36 skin swabs from farmworkers and university students were also collected. PCR was used to confirm the presence of Staphylococcus spp. in all samples. Major species were identified using a species-specific multiplex PCR. An antibiogram assay was performed to determine antibiotic resistance profiles. The overall prevalence of Staphylococcus spp. was 12.18% pre-harvest and 7.54% post-harvest. The most identified species was Staphylococcus epidermidis (19.86%), while most isolates remained unknown (73.90%). Approximately 83.33% of skin swabs were positive for Staphylococcus spp., with Staphylococcus xylosus being the predominant species (16.7%). The highest percentage of isolates were resistant to aminoglycosides and macrolides, with 24.11% of tested samples being multidrug-resistant. S. epidermidis had the most resistance compared to the other species. This study suggests that antibiotic-resistant Staphylococcus spp. is present in mixed farm environments, and proper steps need to be taken to control the transmission between livestock, crops, and humans.

This study evaluated the impact of different food residues on the recovery of Listeria monocytogenes and Salmonella Typhimurium from stainless steel surfaces. Food residues tested include lettuce rinsate, blended lettuce, low-fat milk, and whole milk for Listeria monocytogenes, and powdered infant formula, all-purpose flour, and whole milk dairy powder for Salmonella Typhimurium. Bacterial suspensions were inoculated on stainless steel surfaces with or without food residues and held for different time periods. Significant differences (P < 0.0001) in Salmonella Typhimurium recovery were observed between the no food residue control and all food residues over 24 hours. For Listeria monocytogenes, minimal variability in recovery was observed among food residue types, with significant differences from the no food residue control (P < 0.05) observed after 24 hours. The study also found that surface sampling can spread Listeria monocytogenes and Salmonella Typhimurium on stainless steel surfaces, suggesting that food residue type may affect microbial recovery during environmental monitoring.