Journal of Food Safety最新文献

This study aimed to explore the antibacterial activity and mechanism of chitosan-caffeic acid graft (CS-g-CA) against Staphylococcus aureus (S. aureus). The minimum inhibitory concentration of CS-g-CA against S. aureus was assessed. The results of scanning electron microscope and confocal laser scanning microscope showed that CS-g-CA treatment could destroy the cell morphology and cause the leakage of intracellular contents, leading to bacteria death. The changes of superoxide dismutase, catalase, reactive oxygen species (ROS), and lipid peroxidation indicated that CS-g-CA stimulated the oxidative stress system of the cell, which further induced the generation of ROS, aggravated the accumulation of lipid peroxide, and destroyed the structure of the inner membrane. The electrophoresis results showed that the DNA of bacteria treated with CS-g-CA was broken led to the death of microorganisms. Overall, CS-g-CA has the potential to be a substitute for new bio-preservative with bacteriostatic effects in food industry.

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used for the rapid quantification of multiple mycotoxins, specifically aflatoxins B₁, B₂, G₁, and G₂ (AFB₁, AFB₂, AFG₁, and AFG₂), ochratoxin A (OTA), deoxynivalenol (DON), and zearalenone (ZEN), in walnuts, pistachios, peanuts, coffee beans, rice, and chickpeas from various countries. Total counts of fungi, Aspergillus flavus, and Aspergillus parasiticus were also assessed, along with the effectiveness of a decontamination treatment with inorganic selenium to reduce mycotoxin levels. Of the 78 samples tested, 69% were contaminated with mycotoxins. ZEN, the predominant mycotoxin contaminant, was detected in all the contaminated samples in concentrations often exceeding the maximum level, followed by AFG₁ (28% of the contaminated samples), DON (22%), AFG₂ (11%), and AFB₁ (5.5%). The occurrence of aflatoxins was associated with high proportions of A. flavus and A. parasiticus. Complete removal of AFB₁ from walnuts and DON from roasted coffee beans was achieved by treatment with aqueous selenium, while the levels of ZEN and AFG₁ were respectively lowered by 65% to 89% depending on the commodity and by about 56% in roasted coffee beans. While this novel treatment is a promising approach for mycotoxin decontamination, it is not intended to replace safe practices upstream.

Food is necessary for survival, and contamination can shorten humans' lives on Earth in all dimensions. Real-time screening of food pollutants, such as toxins, infectious agents, and chemical contaminants, is in high demand today. Thus, a cost-effective and ecologically benign technology must be developed to detect food contamination in a rapid fashion. Nanoparticle (NP)-based paper sensors are one of the most important alternatives to traditional methods because these are simple, inexpensive, highly selective, and sensitive tools. This article provides an overview of NP-based paper sensor techniques for detecting toxic food contaminants.

Apple juice samples were treated by pulsed electric field (PEF) alone and in combination with cinnamon essential oils (CEO) at 0.0005, 0.003, and 0.06 μL mL⁻¹ concentrations as a function of treatment time. Results revealed 11 different compounds with the highest concentrations of 44.79% 3-propenal 3-phenyl, 34.98% trans-cinnamaldehyde, and 10.18% 4-propenal 3-phenyl in CEO. pH and total soluble solids of the apple juice samples significantly decreased; whereas total phenolic substance content of the samples significantly increased by added CEO. The same process parameters caused 3.26 ± 0.19 and 3.83 ± 0.16 log reductions on TAMB and TMY, revealing no detectable numbers after PEF treatment. Similarly, maximum 5.13 and 3.87 log reductions on Escherichia coli O157:H7 and Listeria monocytogenes were obtained on 0.06 μL mL⁻¹ CEO added samples treated after 604 μs. Moreover, increased CEO concentration, when treatment time was constant, caused significantly more microbial inactivation. Increase in treatment time resulted in an incline on ΔH of the samples. Response optimization revealed that 604 μs treatment time and 0.06 μL mL⁻¹ concentration were the optimal treatment parameters with 0.63 composite desirability.

The meat processing industry was negatively affected by the COVID-19 pandemic. The unique conditions in meat processing plants (MPPs) were recognized to have the potential to increase SARS-CoV-2 transmission. Should SARS-CoV-2 persist for extended periods in these built environments, this may contribute to increased risk of virus transmission. To test this hypothesis, SARS-CoV-2 persistence was assessed in conditions reflective of a MPP. Different biotic/abiotic materials were inoculated with SARS-CoV-2 and recovery of viable virus measured over time. Findings showed it was possible to recover SARS-CoV-2 from beef, pork, and salmon for at least 22 days at −20°C and for at least 12 days at +4°C. SARS-CoV-2 recovery from salmon scales and salmon flesh was similar, but viable virus recovered from pork fat was significantly reduced compared to pork meat. In parallel, foods purchased from Irish supermarkets during a COVID-19 wave were contemporaneously tested for the presence of SARS-CoV-2 RNA but none of the samples tested positive by RT-qPCR. Viable SARS-CoV-2 can be inactivated on food or abiotic surfaces by incubation at 56°C or 75°C but fomite transmission during MPP outbreaks cannot be ruled out due to the recovery of SARS-CoV-2 from stainless steel and work clothing fabric for up to 10 h under representative conditions. These data support a multilayered approach to reducing the risk of airborne infections such as SARS-CoV-2 that should include mitigations such as increased ventilation, mask wearing, and the disinfection of work surfaces to reduce the amount of SARS-CoV-2 in the meat processing plant environment.

The demand for healthier products by consumers has prompted research into the use of essential oils (EOs), which are known for their antimicrobial properties. This study investigated the antimicrobial properties of EOs as a potential alternative to synthetic preservatives, specifically, cinnamon, clove, and oregano EOs, as well as their majority compounds (cinnamaldehyde, eugenol, and carvacrol) on Clostridium sporogenes inoculated in hams. The findings of the study revealed that cinnamon EO and its major compound cinnamaldehyde were the most efficient in inhibiting the growth of C. sporogenes, demonstrating the lowest minimum bactericidal concentration MBC (0.1%). The combination of oregano EO, cinnamon EO, cinnamaldehyde, and carvacrol led to a significant decrease in bacterial growth (approximately 3 log) after 28 days in hams. Furthermore, the presence of spores was not observed for 14 days (at 14°C) and 21 days (at 7°C) of storage, indicating a delay in sporulation. The treatments using the combination of EOs, and their major compounds had minimal impact on the color of the hams while maintaining the physicochemical characteristics of the product. This study demonstrates that EOs and their major compounds can be applied as natural preservatives in ham, offering a potential alternative for reducing the use of nitrites in various food types. The research emphasizes the antibacterial efficacy of cinnamon, clove, and oregano EOs, along with their major compounds, in inhibiting C. sporogenes in ham. The findings indicate that these natural alternatives could be valuable in preserving food products and reducing the reliance on synthetic preservatives.

In the natural environment, ruminant livestock, including cattle, are the main reservoir of the outbreak–causing strains of Shiga toxin-producing Escherichia coli (STEC), where bacteriophages sustainably thrive as well. This study focuses on the characterization of STEC-specific bacteriophages isolated from cow manure samples in Maine farms and examines their prevalence with STEC hosts. Phenotypic features of representative isolates were characterized by using a transmission electron microscope. Similarly, host range, one-step growth curve, thermal stability, lytic capability, and genomic analyses were performed to fully characterize selected representative isolates. Results showed that representative bacteriophage isolates belong to Myoviridae (S6P10 and S14P12) and Siphoviridae (S19). The most prevalent and common bacteriophages (46%) were specific to the O26 serogroup. The farm C sampling site had highly heterogenous bacteriophage populations that were specific to six STEC serogroups. The most prevalent bacteriophage isolate (S1P5, Escherichia phage vB_EcoM-S1P5QW) was verified to have a double-stranded DNA genome (166,102 bp) with 266 CDs of which 130 have known functions. The majority of the diverse bacteriophage isolates had strong lytic capabilities and a narrow host range that could withstand selected temperature conditions (−20, 37, and 62°C). Results of bacterial screening showed that STEC host strains were not detected in Farms A, C, and E, but were detected on Farms B and D. In conclusion, the highly-diverse bacteriophage ecology found in cow manure samples may have been an important element in shaping the population of STEC serogroups, specifically in its natural environment, which can provide useful tools for potential antibiotic-free therapeutics and diagnostic technologies.

For fresh foods, the purpose and benefits of modified atmosphere packaging (MAP) generally include the preservation of antioxidants, the extension of shelf life, deferral of microbial spoilage, and retention of product color. Commercial MAP products frequently involve a mixture of nitrogen, oxygen, and carbon dioxide, affecting consumer acceptability, cost-effectiveness, and hygienic food safety issues. This study investigated a novel active MAP formulation for strawberries in retail packaging which ensures changes in quality-related physicochemical characteristics [including hardness, moisture, vitamin C, total soluble solids (TSS), titratable acid, and appearance] during low-temperature storage, whereas samples of different storage times were assessed for shelf life by sensory evaluation. The innovative active MAP formulation of 0.8 g of sodium ascorbate, 2.6 g of sodium carbonate, and 1.6 g of ferrous sulfate achieved atmosphere equilibrium in packaged strawberries in <48 h, compared to 5–6 days in the control group. Strawberries treated with active MAP maintained their moisture, firmness, vitamin C, TSS, and titratable acid contents better than the control group (p < 0.05). The strawberries showed softening and waterlogging of tissue and 50% moldiness by the 14th day, while the control group lost commercial value by the 8th. New applications of similar commodities in food are unavailable based on current knowledge. Therefore, the scope of fresh food applications covered in this study and the refinement of other functions will be helpful directions for future research.

In this study, gelatin-based encapsulation of different bioactive compounds including essential oils (EOs) and bacteriocins, produced by lactic acid bacteria was established to evaluate the microbial, physiochemical, and sensory qualities of meatballs. Determination of minimum inhibitory concentration followed by checkboard method showed citrus extract, Mediterranean formulation, Cinnamon and thyme EOs had inhibitory concentrations between 20 and 5000 ppm and synergistic effect against common contaminant and pathogenic bacteria in meat. The bacteriocins produced by Lactobacillus curvatus and Pediococcus acidilactici showed antimicrobial activity between 10,000 and 80,000 ppm against Leuconostoc mesenteroides, Carnobacterium divergens, Lactobacillus curvatus, Listeria inocua, Listeria monocytogenes, and Pseudomonas aeruginosa. Encapsulation of the bioactive compounds in gelatin kept the bioactive content to greater extent. The encapsulated bioactive compounds were effective to inhibit the microbial growth, retard the lipid oxidation and color changes, and preserve the sensorial attributes of meatballs. It can be concluded that gelatin-based encapsulation of Cinnamon EOs and bacteriocins is effective to extend the shelf-life of meatballs.

The antibacterial packaging films were produced from poly (vinyl alcohol) (PVOH), agarose, and cinnamon (Cinnamon cassia) oil (CO). The mechanical, antibacterial, water- and UV-barrier properties of the resulting films were fully characterized. Our findings revealed that increasing amount of CO slightly affected the color of resulting film, while the dispersion of CO in polymeric matrix was influenced by CO concentration. UV-barrier property of PVOH/agarose was enhanced by adding a small amount of CO. Tensile strength of the resulting films insignificantly changed (8.94–10.23 MPa) with raising CO content while the flexibility remarkably dropped from 92.63% to 75.49%. Remarkably, the PVOH/agarose containing 1.5% (v/v) CO presented strong inhibition against Pseudomonas aeruginosa, Escherichia coli, Salmonella typhimurium, and Staphylococcus aureus due to the presence of cinnamaldehyde in CO and this inhibitory efficiency was maintained for up to 7 days. Furthermore, the PVOH/agarose film enriched with 1% (v/v) CO was applied for enhancing the storability of bread slices during 50-day storage at room temperature.