Journal of Food Safety最新文献

Malachite green (MG), a triphenylmethane dye is often used as a fungicide and preservative in fisheries due to its effectiveness against water molds in fish and fish eggs. However, excessive inhalation can be hazardous to human health. To quantify the MG concentration, we created and evaluated a 96-well plate-based chemiluminescence immunoassay (CLIA). This method used provided readings in <30 min, with an optimal incubation time of 15 min and a limit of detection of 0.20 ng·ml⁻¹. The strong correlation (R² >0.99) between the measured values of real fish samples examined using the method and the high-performance liquid chromatography results confirmed the accurate quantitative detection of MG. In this study, CLIA was also used in conjunction with point-of-care testing (POCT) to greatly improve the efficiency of the experiments. Thus, a quantitative detection method based on MG plate chemiluminescence was established herein, with performance indexes that meet the requirements of on-site detection. This approach is also applicable to the detection of small molecule compounds such as chloramphenicol and sulfadiazine pyrimethamine, providing a new direction in the field of food safety detection.

The study investigates the efficacy of lactic acid bacteria (LAB) strains (Lactobacillus rhamnosus and Lactobacillus casei) in combating Escherichia coli biofilms by determining antibacterial, anti-biofilm activity, auto-aggregation, and co-aggregation assay. The study included 115 E. coli isolates from milk (n = 36), chicken meat (n = 33), and chicken eggs (n = 46). Among 115 E. coli isolates, 22.61% were strong biofilm formers. The LAB strain, L. rhamnosus exhibited a 28.47 mm mean antibacterial inhibition zone, an average reduction of 51.22% in biofilm growth, 55.46% auto-aggregation, and 41.57% co-aggregation with E. coli. Similarly, L. casei demonstrated a 21.55 mm mean antibacterial inhibition zone, an average reduction of 36.74% in biofilm growth, 45.23% auto-aggregation, and 38.74% co-aggregation with E. coli isolates. Both strains individually and in combination demonstrate substantial reductions in biofilm growth, with L. rhamnosus observed to be more effective than L. casei. Scanning electron microscopy provides valuable insights into the structural aspects of the probiotic impact on diminishing E. coli biofilm. Probiotics' ability to auto-aggregate and co-aggregate with pathogenic strains serves as an initial screening method for identifying suitable probiotic bacteria. In conclusion, the results underscore the efficacy of specific LAB strains in combating E. coli biofilm formation. This study provides a basis for future investigations into LAB's capacity to mitigate biofilm-related hurdles and strengthen microbial management protocols within food processing settings or relevant food substrates.

In this study, hyperspectral imaging technology combined with a novel convolution neural network was utilized to detect wheat kernels adulteration. Two groups of wheat kernels were used as samples in this study. Sound wheat kernels from various varieties were in one group, while unsound wheat kernels of the same variety were in another. Hyperspectral images collected from these two groups of wheat kernels were preprocessed using a series of commonly used methods. Following the collection of hyperspectral data, a method of separating and recombining individual wheat kernels from entire hyperspectral images was applied to create training sets and validation sets. Subsequently, a series of tests were carried out to verify whether the proposed model Following that, a number of experiments were conducted to confirm if the suggested model was effective in simultaneously detecting adulterated wheat kernels, and the results gave a positive conclusion. Finally, accuracy, precision, recall and F1-scores were used as indicators to evaluate the performance of the proposed models on the test set. As the results demonstrated, satisfactory performance in detecting adulteration of the two groups of wheat kernels was obtained by the proposed model. According to the results, the proposed model combined with HSI technology has a good prospect of being used as an efficient method for detecting wheat kernels adulteration.

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.