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Sampling and Testing

Microbiological Testing of Fresh Produce

In 2010 the United Fresh Food Safety Council developed a White Paper on considerations in developing and using microbiological sampling and testing procedures if used as part of a food safety program for fresh fruit and vegetable products.

Download the 2010 Micro White Paper
The 2010 paper discusses pros and cons of testing in different situations. The 2020 document is a guide food safety professionals can use as a reminder of the numerous factors that should be considered when developing a sampling and testing program to detect pathogens in finished product. This includes the “how-tos” of a testing program, as well as how to interpret, act upon, and communicate a positive finding. Further, consideration should be given to managing supplier and customer expectations, including situations in which they are also testing product.
Download the 2020 White Paper

Most recently, a subgroup of the council began discussing misconceptions, and opportunities, associated with field sampling. This document will be updated as it continues to evolve. 

Download the Draft Field Sampling Misconceptions & Considerations Paper

The subgroup also used outbreak information provided by FDA to reverse engineer a preharvest sampling plan that, with assumptions, could have detected the high level of contamination that presumably caused the outbreak. Visual illustrations and the background calculations are provided to support the explanation of this thought experiment.

Download the Reverse Engineered PreHarvest Sampling Plan Thought Experiment
Download the Visual Illustrations for the Reverse Engineered PreHarvest Sampling Plan Thought Experiment
Download the Calculations that Support the Reverse Engineered PreHarvest Sampling Plan Thought Experiment

Webinars & Trainings

Designing a Sampling and Testing Plan Training

Despite the fact that testing is not a food safety control measure, many companies conduct finished product or raw material testing. However the number of samples that should be taken, what to test for, method to use, and what to do if you get a positive aren’t always well understood. The all-new Designing a Sampling and Testing Plan Training will answer these questions. This one day training, designed specifically for the fresh produce industry, will review the basics of microbiology, describe different method platforms and the method validation process, the statistics behind sampling, lab accreditation, and legal ramifications.

Designing a Sampling and Testing Plan

Statistics of Sampling Webinar (Recorded 4/30/20)
Sampling has become an integral part of food safety testing for the fresh produce industry. But important questions still remain: How many samples to take? How often to sample? How much product to sample? What does N60 really mean? Is Z-pattern sampling the best way to sample a field? Should samples be composited? This webinar delves into this, and more with ample time for Q&A with the presenter. This webinar was sponsored by Ecolab.


Building the case for Zone 1 Listeria sampling in produce operations: A review of regulatory policy and industry strategies Webinar (Recorded 10/1/19)
Unsure how food contact surface (i.e. Zone 1) testing for Listeria spp. can fit into your environmental monitoring plan without exposing your organization to regulatory risk or backlash? Join us for this 1-hr webinar to learn about the changes in regulatory thinking, conveyed via the FDA’s 2017 publication of “Draft Guidance for Industry: Control of Listeria monocytogenes in Ready-To-Eat Foods”, intended to incentivize the ‘seek and destroy’ approach to monitoring for Listeria on food contact surfaces. Still, many in the fresh produce industry (fresh-cut and packinghouses) remain understandably wary of Zone 1 testing. After covering current FDA policy related to environmental monitoring, we’ll provide detail on a new resource in development by a United Fresh workgroup: a set of guidelines and case studies that illustrate how an operation can prepare to implement Zone 1 sampling, and provide strategies for how to react in the event of a positive. After listening to this webinar, attendees should feel more confident in assessing their operation’s ability to move towards testing Zone 1 surfaces for Listeria spp. This webinar was sponsored by Ecolab.


Zone 1 Sampling

As Zone 1 sampling becomes more common within the fresh produce industry, increased guidance and training is needed to ensure testing is done properly. This page includes webinars and trainings, guidance documents, and other resources to provide support to the industry.  Other resources on Listeria Monocytogenes can be found on the United Fresh website.

Following the 2017 release of the FDA’s “Draft Guidance for Industry: Control of Listeria monocytogenes in Ready-To-Eat Foods”, United Fresh published a revised industry guidance for the fresh produce industry. This new edition included more detail around sanitation and sanitary design as well as enhanced discussion of both Zone 1 and finished product testing. In 2019, United Fresh Food Safety Council formed a Zone 1 Sampling working group to develop the following resources to help describe the decision-making processes associated with Z1 sampling and provide recommended approaches in the event of a positive finding.

Zone 1 Sampling Information


For any questions on these resources or to report broken links, contact Katie McGowan, Manager, Food Safety Programs, via email or by phone at (202) 303-3402.