Evaluation of Commercially Available Sanitizers Efficacy to Control Salmonella (Sessile and Biofilm Forms) on Harvesting Bins and Picking Bags.

This study evaluated the efficacy of five commercially available sanitizers to reduce Salmonella (sessile and biofilm forms) count on experimentally inoculated materials representative of harvesting bins and picking bags in the fresh produce industry. Sessile Salmonella cells were grown onto tryptic soy agar to create a bacterial lawn, while multistrain Salmonella biofilms were grown in a Centers for Disease Control and Prevention (CDC) reactor at 22 ± 2 °C for 96 h. Samples were exposed to 500 ppm free chlorine, 500 ppm peroxyacetic acid (PAA), 75 psi steam, and 5% silver dihydrogen citrate (SDC) for 30 sec, 1, or 2 min or 100 ppm chlorine dioxide gas for 24 h.

Escherichia coli Survival on Dry Bulb Onions Treated with Crop Protection Sprays Prepared using Contaminated Water in the Treasure Valley Growing Region.

Contaminated agricultural water has been implicated in produce-associated outbreaks, including dry bulb onions (Allium cepa). This study was designed to quantify risks associated with contaminated water used to prepare crop protection sprays applied immediately before the onset of field curing of dry bulb onions. Laboratory experiments determining the behavior of Salmonella and Escherichia coli in crop protection chemical solutions were performed to guide selection for field use.

Irrigation Method Matters: Contamination and Die-off Rates of Escherichia coli on Dry Bulb Onions After Overhead and Drip Irrigation in Washington State (2022-2023).

Two U.S. outbreaks of salmonellosis in 2020 and 2021 were epidemiologically linked to red onions.

Comparison of Three Air Sampling Methods for the Quantification of Salmonella, Shiga-toxigenic Escherichia coli (STEC), Coliforms, and Generic E. coli from Bioaerosols of Cattle and Poultry Farms.

Recent fresh produce outbreaks potentially associated with bioaerosol contamination from animal operations in adjacent land highlighted the need for further study to better understand the associated risk. The purpose of this research was to evaluate three sampling methods for quantifying target bacterial bioaerosols from animal operations. A dairy cattle and poultry farm located in Georgia, U.

Ranking Food Safety Priorities of the Fresh Produce Industry in the United States.

A broad understanding of community member food safety priorities in the fresh produce supply chain does not currently exist. This information is essential to improve food safety knowledge and practices effectively and efficiently throughout the fresh produce industry; therefore, the goal of this study was to identify and rank community produce safety priorities in the United States. Survey questions were designed and approved by food safety experts for participants to rank 24 fresh produce safety priorities.

Impact of chlorine or peracetic acid on inactivation of Salmonella, Escherichia coli, and Listeria monocytogenes in agricultural water.

Preharvest agricultural water has been recognized as one of the routes of contamination for foodborne pathogens during fruit and vegetable production. Several strategies have been proposed to reduce the risk of pathogens, including preharvest water chemigation, but literature is lacking with regards to microbiological inactivation of common bacterial foodborne pathogens associated with fresh produce contamination, Salmonella enterica, Shiga-toxigenic Escherichia coli (STEC), and Listeria monocytogenes, in surface irrigation water after exposure to chlorine and peracetic acid (PAA). Surface water supplied by a local irrigation district was collected over the summer of 2019.

Efficacy of cleaning and sanitation methods against Listeria innocua on apple packing equipment surfaces.

Previous foodborne listeriosis outbreaks and recalls of fresh produce have been linked to cross-contamination with food contact surfaces (FCS) of packing equipment. Thus, effective cleaning and sanitation practices should be implemented in the short-term to contribute to the overall food safety objective for FCS which have a suboptimal hygienic design. This research aimed to evaluate the efficacy of seven cleaning and sanitation treatment combinations against Listeria innocua populations on FCS common to produce packinghouses that have been found to have a higher prevalence of Listeria spp.

Persistence of Listeria innocua on Fresh Apples during Long-Term Controlled Atmosphere Cold Storage with Postharvest Fungal Decay.

Abstract: Recent apple-related recall and outbreak events have exposed a need for better food safety controls along the supply chain. Following harvest, apples can be stored under a controlled atmosphere for up to 1 year after harvest before packing and distribution, making the crop susceptible to many opportunities for contamination that increase the quantity of postharvest losses. Botrytis cinerea and Penicillium expansum cause significant rot-associated losses to the apple industry.

Prevalence of Species on Food Contact Surfaces in Washington State Apple Packinghouses.

The 2014 caramel apple listeriosis outbreak was traced back to cross-contamination between food contact surfaces (FCS) of equipment used for packing and fresh apples. For Washington state, the leading apple producer in the United States with 79% of its total production directed to the fresh market, managing the risk of apple contamination with within the packing environment is crucial. The objectives of this study were to determine the prevalence of spp.

Prevalence of Salmonella enterica in Flies on a Diversified Cattle and Fresh Produce Farm across Two Growing Seasons.

Abstract: Flies are a vector for spreading foodborne pathogens pertinent to fresh produce, such as Shiga toxigenic Escherichia coli and Salmonella; however, most studies focus on concentrated animal feeding operations, which do not reflect low-density animal farming practices that often adjoin fruit and vegetable acreage. In this study, we determined the prevalence of Salmonella in flies collected biweekly on an integrated animal and produce operation over two growing seasons. Eleven of 889 pooled samples tested positive for Salmonella.

Utility of rapid tests to assess the prevalence of indicator organisms (Aerobic plate count, Enterobacteriaceae, coliforms, Escherichia coli, and Listeria spp.) in apple packinghouses.

The 2014 listeriosis outbreak caused by caramel-coated apples was linked to apples cross-contaminated within an apple packing facility. This outbreak has increased the focus on effective cleaning and sanitation methods that must be validated and monitored during apple packing. Thus, rapid and reliable testing methods are necessary for assessing cleanliness in the apple packing industry.

Optimization of a Method for the Concentration of Genetic Material in Bacterial and Fungal Communities on Fresh Apple Peel Surfaces.

Apples are the most consumed fruit in the United States and have recently been shown to exhibit some vulnerability to contamination across the supply chain. It is unclear what role a fruit microbiome analysis may serve in future food safety programs interested in understanding changes in the product and the processing environment. Ultimately, sample integrity is key if any of these approaches are to be employed; low microbial loads on apple surfaces, the inability to sample the entire surface, and inefficiency of removal may act as barriers to achieving high-quality DNA.

Transcriptomic Behavior of Salmonella enterica Newport in Response to Oxidative Sanitizers.

Abstract: Agricultural water is a known source of contamination to fresh produce and can contain foodborne pathogens including Salmonella enterica, pathogenic Escherichia coli, Listeria monocytogenes, and Campylobacter jejuni. To mitigate such risks, antimicrobial agents such as hypochlorites and peroxyacetic acid (PAA) can be applied to in-line irrigation systems as well as to water used in postharvest washing. Although these compounds are effective and widely used, some pathogenic bacteria adapt to survive exposure.

Potential of Cinnamon Oil Emulsions as Alternative Washing Solutions of Carrots.

The objective of this study was to evaluate the potential of cinnamon oil emulsions as alternative washing solutions to improve the microbial safety of carrots. Whey protein concentrate (WPC), gum arabic (GA), lecithin, and their combinations were used to prepare cinnamon oil emulsions. The emulsions were characterized for their hydrodynamic diameter (D) during 7 days of storage and their antimicrobial activity against cocktails of Salmonella enterica , Escherichia coli O157:H7, and Listeria monocytogenes .

Quality attributes and microbial survival on whole cantaloupes with antimicrobial coatings containing chitosan, lauric arginate, cinnamon oil and ethylenediaminetetraacetic acid.

Cantaloupes are susceptible to microbiological contamination in pre- or postharvest environments. Novel intervention strategies, such as antimicrobial coatings, are needed to improve the microbiological safety of cantaloupes. The objective of this study was to prepare whole cantaloupes coated with mixtures containing chitosan, lauric arginate (LAE), cinnamon oil (CO), and ethylenediaminetetraacetic acid (EDTA) and determine survival characteristics of inoculated foodborne pathogens during storage as well as cantaloupe quality attributes.

Antimicrobial Efficacy of an Array of Essential Oils Against Lactic Acid Bacteria.

The essential oils of clove bud, cinnamon bark and thyme, and their individual compounds including allyl isothiocyanate (AIT), carvacrol, cinnamaldehyde, cinnamic acid, eugenol, and thymol were initially assessed for antimicrobial activity against 9 lactic acid bacteria (LAB) species. Carvacrol and thymol were the most inhibitory with MICs of 0.1% (v/v and w/v, respectively).

Effect of alginate coatings with cinnamon bark oil and soybean oil on quality and microbiological safety of cantaloupe.

The quality and microbiological safety of cantaloupes can potentially be improved using antimicrobial coatings that are able to maintain effectiveness throughout storage. The objective of this work was to study the effect of coating mixtures containing sodium alginate and cinnamon bark oil (CBO) on the quality of cantaloupes and the survival of inoculated bacterial pathogens and naturally occurring yeasts and molds during ambient storage at 21 °C. Cantaloupes were dipped in mixtures containing 1% sodium alginate with or without 2% CBO and 0 or 0.

Antimicrobial Activity of Cinnamaldehyde, Carvacrol, and Lauric Arginate against Salmonella Tennessee in a Glycerol-Sucrose Model and Peanut Paste at Different Fat Concentrations.

The objective of this study was to investigate the antimicrobial activities of carvacrol, cinnamaldehyde, and lauric arginate (LAE) against Salmonella in a low water activity (aw ) glycerol-sucrose model and in peanut paste with different fat concentrations. Salmonella Tennessee was inoculated into the model and the low fat (<5%) and high fat (50%) peanut paste adjusted to aw 1.0, 0.

Formulating essential oil microemulsions as washing solutions for organic fresh produce production.

Applications of plant-derived organic essential oils (EOs) as antimicrobials for post-harvest produce operations are limited by their low water solubility. To dissolve EOs in water, microemulsions were studied using two surfactants permitted for organic production, sucrose octanoate ester (SOE) and soy lecithin that were mixed at various mass ratios before dilution with water to 40% w/w. EOs were then mixed with the surfactant solution by hand shaking.

Self-emulsification of alkaline-dissolved clove bud oil by whey protein, gum arabic, lecithin, and their combinations.

Low-cost emulsification technologies using food ingredients are critical to various applications. In the present study, a novel self-emulsification technique was studied to prepare clove bud oil (CBO) emulsions, without specialized equipment or organic solvents. CBO was first dissolved in hot alkaline solutions, added at 1% v/v into neutral solutions with 1% w/v emulsifier composed of whey protein concentrate (WPC), gum arabic, lecithin, or their equal mass mixtures, and adjusted to pH 7.

Survival of Salmonella enterica in poultry feed is strain dependent.

Feed components have low water activity, making bacterial survival difficult. The mechanisms of Salmonella survival in feed and subsequent colonization of poultry are unknown. The purpose of this research was to compare the ability of Salmonella serovars and strains to survive in broiler feed and to evaluate molecular mechanisms associated with survival and colonization by measuring the expression of genes associated with colonization (hilA, invA) and survival via fatty acid synthesis (cfa, fabA, fabB, fabD).

Naturally occurring antimicrobials for minimally processed foods.

Natural antimicrobials are gaining increased interest from researchers and food manufacturers alike seeking to discover label-friendly alternatives to the widely implemented synthetic compounds. Naturally occurring antimicrobials can be applied directly to food to protect food quality, extend food shelf life by inhibiting or inactivating spoilage microorganisms, and improve food safety by inhibiting or inactivating food-borne pathogens. There are a great number of natural antimicrobials derived from animal, plant, and microbial sources.

Increased transcription of the phosphate-specific transport system of Escherichia coli O157:H7 after exposure to sodium benzoate.

Sodium benzoate is a widely used food antimicrobial in drinks and fruit juices. A microarray study was conducted to determine the transcriptional response of Escherichia coli O157:H7 to 0.5% (wt/vol) sodium benzoate.

Microbial ecology of foodborne pathogens associated with produce.

The recent recognition of fresh fruits and vegetables as major vehicles of foodborne illness has led to increased research on mechanisms by which enteric pathogens contaminate and persist on and in this non-host environment. Interactions between foodborne pathogens and plants as well among the naturally occurring microbial communities contribute to endophytic and epiphytic colonization. Scientific findings are just beginning to elucidate the mechanisms that contribute to colonization of produce.