Food Safety
search
cart
facebook twitter linkedin
  • Sign In
  • Create Account
  • Sign Out
  • My Account
Food Safety
  • NEWS
    • Latest News
    • White Papers
  • PRODUCTS
  • TOPICS
    • Contamination Control
    • Food Types
    • Management
    • Process Control
    • Regulatory
    • Sanitation
    • Supply Chain
    • Testing and Analysis
  • PODCAST
  • EXCLUSIVES
    • Food Safety Five Newsreel
    • eBooks
    • FSM Distinguished Service Award
    • Interactive Product Spotlights
    • Videos
  • BUYER'S GUIDE
  • MORE
    • ENEWSLETTER >
      • Archive Issues
      • Subscribe to eNews
    • Store
    • Sponsor Insights
  • WEBINARS
  • FOOD SAFETY SUMMIT
  • EMAG
    • eMagazine
    • Archive Issues
    • Editorial Advisory Board
    • Contact
    • Advertise
  • SIGN UP!
NewsContamination ControlFood TypeMicrobiologicalCross-ContaminationProduce

Researchers Studying Cross-Contamination in Dry Produce Packinghouse Environments

By Food Safety Magazine Editorial Team
pile of onions

Image credit: mayu ken via Unsplash

October 25, 2023

An ongoing study funded by the Center for Produce Safety (CPS) is looking to fill knowledge gaps about the potential for microbial cross-contamination in dry produce packinghouse environments, and to produce science-based information that packers can use to devise risk assessments and mitigation strategies. The study is led by Nitin Nitin, Ph.D., with the University of California, Davis (UC Davis).

The project involves laboratory experiments with yellow onions and peaches, as well as two different surface materials typically found in packinghouses. Onions are packed under entirely dry conditions, while peach processing has a combination of a wet wash and dry packaging. The research results could be applied to any produce commodities that undergo a portion of handling and packaging under dry conditions.

Because bacteria act differently in a dry environment than when water is present, how pathogens move from produce to a food surface, or from a food contact surface to produce, is something that needs to be better understood.

Co-principal investigator on the study, Linda Harris, Ph.D. of UC Davis, is also collaborating with Oregon State University on another CPS-funded project that examines how production practices affect dry bulb onion safety. Between the two projects, Dr. Nitin said the research provides a continuum of what happens in the field and what happens in the packinghouse.

In the laboratory, the researchers are focusing on Salmonella because the pathogen is known to survive for long periods in dry environments compared to Escherichia coli or Listeria monocytogenes, which do not do well under similar settings. The researchers are also using the surrogate organism Enterococcus faecium so they can benchmark their results against standard and acceptable practices.

The experiments are designed to mimic cross-contamination that may occur in a dry packinghouse environment. The researchers measured microbial transfer from simulated packing surfaces—specifically, stainless steel and common plastic surfaces such as polyurethane—to onions and stone fruit. The researchers also assessed the transfer rate from inoculated produce items to packinghouse surfaces.

The treatments were held under a range of conditions and durations to measure bacterial die-off. The time period was selected to reflect the 2- to 3-month-long onion packing season.

The researchers also examined the influence of onion juice on packing surfaces in influencing the transfer of bacteria from the surface to onions. Surprisingly, they observed that the presence of onion juice enhances the transfer rate of bacteria compared to surfaces without onion juice. However, the researchers did not observe any significant inhibition of the inoculated bacteria in the presence of onion juice.

Although the results are preliminary, the researchers found bacterial species and transfer direction significantly influenced microbial movement between the produce and contact surfaces. The inoculum carrier—whether nutrient broth, onion extract, or a soil-water mixture—also played a role in transfer.

One of the main preliminary findings is that the transfer rate in a dry environment is significantly lower than in a wet environment, from what is reported in the literature.

KEYWORDS: Center for Produce Safety onions peaches study

Share This Story

Looking for a reprint of this article?
From high-res PDFs to custom plaques, order your copy today!

Fsm purple logo 200x200

The Food Safety Magazine editorial team comprises Bailee Henderson, Digital Editor ✉; Adrienne Blume, M.A., Editorial Director; and Stacy Atchison, Publisher.

Recommended Content

JOIN TODAY
to unlock your recommendations.

Already have an account? Sign In

  • people holding baby chicks

    Serovar Differences Matter: Utility of Deep Serotyping in Broiler Production and Processing

    This article discusses the significance of Salmonella in...
    Food Type
    By: Nikki Shariat Ph.D.
  • woman washing hands

    Building a Culture of Hygiene in the Food Processing Plant

    Everyone entering a food processing facility needs to...
    Personal Hygiene/Handwashing
    By: Richard F. Stier, M.S.
  • graphical representation of earth over dirt

    Climate Change and Emerging Risks to Food Safety: Building Climate Resilience

    This article examines the multifaceted threats to food...
    Management
    By: Maria Cristina Tirado Ph.D., D.V.M. and Shamini Albert Raj M.A.
Subscribe For Free!
  • eMagazine Subscription
  • Subscribe to eNewsletter
  • Manage My Preferences
  • Website Registration
  • Subscription Customer Service

More Videos

Sponsored Content

Sponsored Content is a special paid section where industry companies provide high quality, objective, non-commercial content around topics of interest to the Food Safety Magazine audience. All Sponsored Content is supplied by the advertising company and any opinions expressed in this article are those of the author and not necessarily reflect the views of Food Safety Magazine or its parent company, BNP Media. Interested in participating in our Sponsored Content section? Contact your local rep!

close
  • Two men standing in a produce storage facility having a discussion.
    Sponsored byOrkin Commercial

    Staying Compliant With FSMA

  • Deli Salads
    Sponsored byCorbion

    How Food Safety is Becoming the Ultimate Differentiator in Refrigerated and Prepared Foods

Popular Stories

FoodSafetyMattersFinal-900x550-(002).jpg

Ep. 195. Dr. Christopher Daubert: The Value of a Food Science Education

Students returning their lunch trays in a cafeteria

California Bill Would Remove Ultra-Processed Foods from School Lunches

Two men standing in a produce storage facility having a discussion.

Staying Compliant With FSMA

Events

June 26, 2025

How to Design and Conduct Challenge Studies for Safer Products and Longer Shelf Life

Live: June 26, 2025 at 2:00 pm EDT: During this webinar, attendees will learn how to conduct challenge studies for microbial spoilage and pathogen growth, including the common challenges encountered, laboratory selection, and use of predictive models.

May 11, 2026

The Food Safety Summit

Stay informed on the latest food safety trends, innovations, emerging challenges, and expert analysis. Leave the Summit with actionable insights ready to drive measurable improvements in your organization. Do not miss this opportunity to learn from experts about contamination control, food safety culture, regulations, sanitation, supply chain traceability, and so much more.

View All

Products

Global Food Safety Microbial Interventions and Molecular Advancements

Global Food Safety Microbial Interventions and Molecular Advancements

See More Products
Environmental Monitoring Excellence eBook

Related Articles

  • lettuce leaf up close

    Researchers Developing Model to Evaluate Contamination Risks and Control Strategies Along Produce Supply Chain

    See More
  • peaches in a crate

    Researchers Studying Efficacy of Sanitizers, Wash Practices Used at Peach Packinghouses

    See More
  • common blackbird

    Researchers Developing Automatic AI Deterrent Technology for High-Risk Birds in Produce Fields

    See More

Related Products

See More Products
  • food safety.jpg

    Food Safety Contaminants and Risk Assessment

  • food-safety-making.jpg

    Food Safety: Making Foods Safe and Free From Pathogens

  • 9781498762878.jpg

    Food Safety and Protection

See More Products

Events

View AllSubmit An Event
  • August 29, 2024

    Understanding and Addressing Biofilm Communities and Behavior in the Food Plant

    On Demand: In this webinar, speakers with expertise in industry food safety, sanitation, and genomics will provide education on the formation and behavior of biofilms and the challenges they pose to food safety and sanitation operations.
View AllSubmit An Event

Related Directories

  • Cognituv

    Cognituv delivers evidence-based intelligent IoT-enabled UV-C disinfection solutions, partnering with facility managers with our proven process to elevate hygiene and achieve ESG goals. Our US-made products focus on disinfection, and enhanced operations, for optimizing sustainability to scale.
  • Hygiena

    At Hygiena®, our mission is to create innovative diagnostics for a healthier world, providing critical solutions that uphold safety and quality standards across various industries. Our suite of products includes the SureTrend® data analysis platform, ATP cleaning verification, allergen detection, molecular diagnostics and product quality tools. These solutions are designed to help you see the bigger picture and make timely decisions to protect your customers and your brand.
×

Never miss the latest news and trends driving the food safety industry

eNewsletter | Website | eMagazine

JOIN TODAY!
  • RESOURCES
    • Advertise
    • Contact Us
    • Directories
    • Store
    • Want More
  • SIGN UP TODAY
    • Create Account
    • eMagazine
    • eNewsletter
    • Customer Service
    • Manage Preferences
  • SERVICES
    • Marketing Services
    • Reprints
    • Market Research
    • List Rental
    • Survey/Respondent Access
  • STAY CONNECTED
    • LinkedIn
    • Facebook
    • Instagram
    • X (Twitter)
  • PRIVACY
    • PRIVACY POLICY
    • TERMS & CONDITIONS
    • DO NOT SELL MY PERSONAL INFORMATION
    • PRIVACY REQUEST
    • ACCESSIBILITY

Copyright ©2025. All Rights Reserved BNP Media.

Design, CMS, Hosting & Web Development :: ePublishing