Category Archives: Decontamination Microbial

Research – When the E. coli hits the fan! Evaluating the risks of dust-associated produce cross-contamination

Posted on November 2, 2021 by | Leave a comment

CPS

Dust represents an understudied vehicle for microbial dispersal and produce contamination by pathogens. Dust deposition onto crops during cultivation is inevitable as plant surfaces serve as a major aerosol sink and dust can serve as a vehicle for bacteria. Wind-driven distribution of dust in agricultural environments can also impact food safety when the sources of dust include particles from natural and human-related reservoirs of pathogens. While the populations of enteric pathogens in water is frequently determined and the microbiological quality of soils are monitored, the evaluation of dust and soil-borne particulates is rarely conducted. This study proposes the following: 1). To evaluate the role of dust in transferring foodborne pathogens to produce surfaces grown in eastern and western regions of the US, 2). To determine the role of humidity in the deposition of dust on produce and the survival of pathogens in dust, and 3). To test dust particulates from animal operations in both regions for the presence of biomarkers indicative of fecal contamination and potentially the presence of pathogens. This study will enhance our understanding of pathogen transport from feces into and through produce fields and will quantify the risk associated with contamination from dust under varying environmental/atmospheric conditions.

Technical Abstract

Dust, broadly defined as fine particulate matter resulting from wind erosion on land surfaces and suspended in the air, is an inseparable component of the atmosphere. Dust represents an understudied vehicle for microbial dispersal in agricultural environments and produce contamination by microorganisms pathogenic to humans. Dust not only affects biological processes in plants, such as stomatal gas exchange, but also the plant surface microbiome. Dust deposition onto crops during field cultivation is inevitable as plant surfaces serve as a major aerosol sink. Studies have indicated that dust can serve as a vehicle for bacteria. Wind-driven distribution of dust in agricultural environments could also impact food safety when the sources of dust include particles from natural (soil, decaying vegetation, feral/wild animal droppings) and human-related (manure-amended soils, silage, municipal sewage-based biosolids, composting, and animal production facilities) reservoirs of human pathogens. While the populations of enteric pathogens in water is frequently determined through periodic testing as recommended by the Food Safety Modernization Act (FSMA) and the microbiological quality of soils are monitored, the evaluation of dust and soil borne particulates is rarely carried out. This study proposes the following: 1). To evaluate the role of dust in transferring foodborne pathogens to the surfaces of produce commodities specific to the eastern and western agricultural regions of the United States, 2). To determine the role of humidity in the deposition of dust on produce and the survival of foodborne pathogens in dust particulates, and 3). To test dust particulates from animal operations in Georgia and Arizona for the presence of biomarkers indicative of fecal contamination and the presence of enteric pathogens. This project will enhance our understanding of pathogen transport from feces into and through produce fields and will quantify the risk associated with contamination from dust under varying environmental and atmospheric conditions.

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Posted in Decontamination Microbial, E.coli, food contamination, Food Hazard, Food Hygiene, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiome, Research, Uncategorized

Research – Nanotechnology as a Processing and Packaging Tool to Improve Meat Quality and Safety

Posted on November 1, 2021 by | Leave a comment

MDPI

Nanoparticles are gaining momentum as a smart tool towards a safer, more cost-effective and sustainable food chain. This study aimed to provide an overview of the potential uses, preparation, properties, and applications of nanoparticles to process and preserve fresh meat and processed meat products. Nanoparticles can be used to reinforce the packaging material resulting in the improvement of sensory, functional, and nutritional aspects of meat and processed meat products. Further, these particles can be used in smart packaging as biosensors to extend the shelf-life of fresh and processed meat products and also to monitor the final quality of these products during the storage period. Nanoparticles are included in product formulation as carriers of health-beneficial and/or functional ingredients. They showed great efficiency in encapsulating bioactive ingredients and preserving their properties to ensure their functionality (e.g., antioxidant and antimicrobial) in meat products. As a result, nanoparticles can efficiently contribute to ensuring product safety and quality whilst reducing wastage and costs. Nevertheless, a wider implementation of nanotechnology in meat industry is highly related to its economic value, consumers’ acceptance, and the regulatory framework. Being a novel technology, concerns over the toxicity of nanoparticles are still controversial and therefore efficient analytical tools are deemed crucial for the identification and quantification of nanocomponents in meat products. Thus, migration studies about nanoparticles from the packaging into meat and meat products are still a concern as it has implications for human health associated with their toxicity. Moreover, focused economic evaluations for implementing nanoparticles in meat packaging are crucial since the current literature is still scarce and targeted studies are needed before further industrial applications. View Full-Text

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Posted in Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research

Research – The combined effect of green tea and peppermint oil against pathogenic bacteria to extend the shelf life of eggs at ambient temperature and the mode of action

Posted on October 29, 2021 by | Leave a comment

Wiley Online

This work investigated the antimicrobial activities of green tea (GT) at 5 and 10.0% wt/vol and peppermint oil (PP) at 0.1, 0.15, and 0.2% wt/vol against major pathogen bacteria (Escherichia coli, Salmonella enteritidis, and Staphylococcus aureus) found on eggs at room temperature (30°C). The quality factors (weight loss, Haugh unit, albumen pH, egg yolk, and albumen index) of treated eggs were also measured while they were stored at room temperature for 14 days. A 9-point hedonic scale was used for sensory evaluation. Scanning electron microscopy was used to examine the morphology of bacteria cells to understand this study’s mechanism of action. It was found that combining 10% GT and 0.15% PP had complete antibacterial activity against all pathogenic bacteria investigated, and could extend the shelf life of treated eggs from 7 days (control) to at least 14 days. The treated egg’s coliforms (≤3.0 log10 colony-forming unit [CFU] g−1), E. coli (≤1.8 log10 CFU g−1), TVC (≤4.3 log10 CFU g−1), Salmonella spp., (not detected in 25 g), and S. aureus (not detected in 25 g) were better able to meet the microbiological criteria for egg after 14 days of storage, when compared to the control, which exceeded the criteria within 7 days. In addition, consumers rated egg acceptability as favorable by giving a sensory score ranging from like slightly to like moderately (~6.7). Furthermore, when compared to the control (6–7 days), all treated eggs retained their quality during storage for 14 days and met the microbiological criteria for egg in food standard (<4.7–6.0 log10 CFU g−1 for total visible count). Compound leakage from within the bacteria, which was the mode of action when GT and PP were combined, resulted in a wrinkled appearance of bacteria cells and serious defects in bacteria membrane morphology. These findings suggest that a sanitizing spray derived from GT and PP can extend the shelf life of eggs and ensure their safety for human consumption at room temperature without using a refrigerator.

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Posted in Decontamination Microbial, E.coli, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Technology, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, Salmonella, Staphylococcus aureus, Technology

Research – New Trends in Photodynamic Inactivation (PDI) Combating Biofilms in the Food Industry—A Review

Posted on October 26, 2021 by | Leave a comment

MDPI

Biofilms cause problems in the food industry due to their persistence and incompetent hygiene processing technologies. Interest in photodynamic inactivation (PDI) for combating biofilms has increased in recent years. This technique can induce microbial cell death, reduce cell attachment, ruin biofilm biomolecules and eradicate structured biofilms without inducing microbial resistance. This review addresses microbial challenges posed by biofilms in food environments and highlights the advantages of PDI in preventing and eradicating microbial biofilm communities. Current findings of the antibiofilm efficiencies of this technique are summarized. Additionally, emphasis is given to its potential mechanisms and factors capable of influencing biofilm communities, as well as promising hurdle strategies.

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Posted in Biofilm, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Technology, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, PDI, photodynamic inactivation, Research

Research – Use of Acetic Acid to Partially Replace Lactic Acid for Decontamination against Escherichia coli O157:H7 in Fresh Produce and Mechanism of Action

Posted on October 16, 2021 by | Leave a comment

MDPI

Escherichia coli O157:H7 is frequently detected in ready-to-eat produce and causes serious food-borne diseases. The decontamination efficacy of lactic acid (LA) is clearly established. In this study, LA was mixed with acetic acid (AA) to reduce costs while achieving consistent or better inhibitory effects. Time-kill curves and inoculation experiments using fresh-cut spinach and arugula indicated that 0.8%LA+0.2%AA shows similar antibacterial effects to those of 1%LA. To determine whether 1%LA and 0.8%LA+0.2%AA exert antibacterial effects by similar mechanisms, proteomics analysis was used. The proteins related to macromolecule localization, cellular localization, and protein unfolding were uniquely altered after the treatment with 1%LA, and the proteins related to taxis, response to stress, catabolic process, and the regulation of molecular function were uniquely altered after the treatment with 0.8%LA+0.2%AA. Based on these findings, combined with the results of a network clustering analysis, we speculate that cell membrane damage is greater in response to LA than to 0.8%LA+0.2%AA. This prediction was supported by cell membrane permeability experiments (analyses of protein, nucleotide, ATP, and alkaline phosphatase leakage), which showed that LA causes greater membrane damage than 0.8%LA+0.2%AA. These results provide a theoretical basis for the application of an acid mixture to replace LA for produce decontamination. View Full-Text

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Posted in Decontamination Microbial, E.coli O157, E.coli O157:H7, Food Micro Blog, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Technology, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, Technology, Uncategorized

Research – A pilot-scale evaluation of using gaseous chlorine dioxide for decontamination of foodborne pathogens on produce and low-moisture foods

Posted on October 9, 2021 by | Leave a comment

Wiley Online

Small-scale studies have shown that chlorine dioxide gas, ClO2(g), was effective for decontamination of produce, nuts, and spices. This study conducted a pilot-scale evaluation to identify effective ClO2(g) treatment parameters for commercial-scale applications. The gas was produced by a generator utilizing sodium chlorite and chlorine gas for decontamination of Shiga toxin-producing Escherichia coli (STEC), Listeria monocytogenes, and Salmonella inoculated on tomatoes, blueberries, baby-cut carrots, almonds, and peppercorns. Inoculated samples and 45 kg tomatoes in a 1,246-L treatment chamber were exposed to various ClO2(g) concentrations (mg/L) and times 9 (hr) at 70–95% RH to determine the treatment effects on the pathogen reductions. Results showed that the treatment caused higher reductions on produce. A ClO2(g) treatment of 1 mg/L-3 hr at 70% RH reduced 4.9–6.8, 5.1–5.6, and 4.2–6.3 log CFU/g of STEC, L. monocytogenes, and Salmonella, respectively, on produce, with the highest reductions on baby-cut carrots. For almonds and peppercorns, ClO2(g) treatments under higher RH caused higher reductions. The treatment of 2 mg/L-9 hr or 3 mg/L-4 hr at 95% RH reduced >4.0 log of STEC and Salmonella on almonds, and 1 mg/L-5 hr at 85% RH achieved >5.0 log reductions on peppercorns. Applying moisture to the surfaces of almonds caused >4.0 log reductions using 1 mg/L-5 hr at 95% RH. This study identified effective ClO2(g) treatment parameters for achieving >4.0 log reductions of common pathogens on tomatoes, blueberries, baby-cut carrots, almonds, and peppercorns and showed that ClO2(g) generator is suitable for large-scale decontamination. These findings can be used for pilot-scale ClO2(g) decontamination of these products and for testing using ClO2(g) for commercial-scale decontamination trials.

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Posted in Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Technology, Listeria, Listeria monocytogenes, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, Salmonella, Technology