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    New Round of CPS Food Safety Research

    Wednesday, May 4th, 2011

    Meg Miller:
    Hello, this is PMA public relations manager Meg Miller, and welcome back to our audio blog, “Ask Dr. Bob” with PMA’s Chief Science & Technology Officer Dr. Bob Whitaker. We have joining us special guest, Bonnie Fernandez-Fenaroli, Executive Director of the Center for Produce Safety at the University of California, Davis. Dr. Bob chairs the center’s Technical Committee and is a member of the center’s Executive Committee. The CPS has just closed its 2011 request for food safety research proposals at the end of March.

    Bob, Bonnie, what should our listeners know about this new round of research request?

    First, Meg, let me set the stage…CPS and its partners sponsor research activities designed to fill basic knowledge gaps in specific areas of food safety practices for fruit, vegetable and tree nut production, harvest and post-harvest handling. The objective is to provide the produce industry with practical, translatable information that can be used at all levels throughout the supply chain. To date, CPS has funded 43 research projects with a total investment of nearly $6.8 million.

    That’s right Bob. Now, the center and its public and industry research partners are making $3 million available to fund general and commodity-specific projects to address additional food safety research needs in the fresh produce industry. It’s important to note that this is a global research effort. We want to reach out as widely as possible geographically. In the past we’ve had institutions in Israel and Canada doing some of the research.

    Bonnie, can you tell us what specifically the new funding request is looking for?

    The 2011 RFP seeks to fund both produce-general food safety questions and commodity-specific questions. Core research priorities for produce in general look to better understand risk potential and to develop more effective food safety management tools in the following areas:

    • The use and cultivation practices regarding compost, soil amendment and fertilizer,
    • Buffer zones for domesticated animals,
    • Co-management of food safety and the environment,
    • Water,
    • Harvest practices,
    • Post-harvest produce cooling methods,
    • Post-harvest transfer of pathogens via water used during handling and processing, and
    • The significance of “positive” product test results and actual capacity to cause illness.

    And, this RFP’s commodity-specific food safety research pertains to almonds, tree fruit, leafy greens, pistachios, strawberries tomatoes, and a number of different commodities.

    How did research priorities get set?

    The RFP’s general research priorities were identified in industry risk assessments and prioritized by the CPS Technical Committee, an independent advisory board including experts from industry, academia, government and nongovernmental organizations. That group revisits those priorities on an ongoing basis to ensure they main current. The commodity-specific research priorities were developed with industry partners. 

    The CPS Technical Committee and our research partners have a wealth of information to base decisions on. After the first CPS Symposium last year, we hosted an event with FDA to review the state of food safety knowledge in different areas.  That event gave us some ideas on where more research needed to be done. On top of that, both Bonnie and I talk with people throughout the course of the year and take this input to the CPS.  We also look back on what we’ve already funded, as well as research by others, to see if topics have been sufficiently covered or if more needs to be done. The program works very hard to stay current, be flexible, and ensure it addresses the most urgent food safety research needs and issues.

    When will these projects be implemented?

    Proposals were due the 31st of March, and we’ll be announcing the awarding of the projects in the fall of 2011. Projects are typically one to two years but some can be shorter.  We want to be flexible to ensure we accomplish whatever research needs to be done.

    These projects all have a pretty quick research time frame, and that indicates the practical focus of this research. We want to be very timely and very hands-on because we’re dealing with the issues growers and processors face every day.

    So how does all this research fit in with the real-world produce industry?

    Well, Meg, as CPS’ research programs mature, our projects represent a greater and greater part of the produce chain. We initially started with production, then added processing, and we’ll continue to identify needs further along the chain. 

    This is such an important concept. One thing the history of outbreaks in recent years has taught us, is that we’re all in this together. So, while research looking at the survival of pathogens in a field may not seem important to someone who runs a store or restaurant, it’s actually as crucial to them as it is to the grower.  People at all points of the supply chain are affected by food safety issues. The entire industry is indeed tied together, so research at all those various points is important.

    CPS also recognizes the need to evaluate research and determine when decisions can be made from the results. That’s where the CPS Symposium comes in and we’ll talk more about that next time.

    We will definitely look forward to it. Thank you Bonnie and Bob for sharing with us today how this next round of research is important to our industry. Listeners, for more information on the CPS research or the upcoming symposium, go to www.cps.ucdavis.edu.
    Thanks for joining us!

    Product Testing, Part 8: Sampling is a Challenge

    Tuesday, February 15th, 2011

    Julia Stewart:
    Hello, this is PMA PR Director Julia Stewart, and welcome back to our “Ask Dr. Bob” audio blog series on product testing, “with PMA’s Chief Science and Technology Officer Dr. Bob Whitaker. This post is part of a series we’ve been doing on the topic of product testing. Bob, in several posts now you have indicated that sampling is actually a more significant challenge than actual testing…Tell us more.

    Julia, as we’ve talked about earlier in this series, the specificity and selectivity of pathogen tests is only half the equation – the other half is your sampling program or the method you use to collect fruit and vegetable material to be tested. From our previous posts, I think you can all see there are many challenges and benefits associated with the actual pathogen tests. Yet in many ways developing a sampling methodology that can achieve statistically significant confidence levels is more troublesome.

    So, let’s start with what we know … Based on the millions of pounds of produce harvested, shipped and consumed each day by millions of people throughout the country without illness, we know that the frequency of pathogen contamination is low. We also know from data shared at the Center for Produce Safety’s Research Symposium in June 2010 that pathogens do not survive well in production environments.  Indeed, two days after purposely spraying attenuated E. coli O157:H7 on leafy greens crops, researchers could only recover it by using enrichment techniques.  (By the way, “attenuated” means the pathogen’s disease-causing gene has been deactivated so the bacteria can be used in testing without risking making anyone sick.)

    So, because we face both low-frequency contamination and low pathogen survivability, it’s crucial for our sampling methods to be constructed so we can detect even sporadic, low levels of key pathogens. Further, contamination – when it does occur – it is not uniform. When contamination is found in a field, it tends to be random and isolated. That in turn can make follow-up testing a big challenge. Leafy greens growers commonly report following up on confirmed positive tests with extensive field or finished product-level sampling only to find that the  initial positive test results are seldom repeated.  The key to understanding sampling issues in produce is to understand the size of typical production lots or finished product production runs. 

    Just think about a single production block of fresh spinach. Let’s say the block is 10 acres in size; that’s about a day’s harvest for a small to medium size producer.  Planted at a density of about 4 million plants to the acre, our production block has approximately 40 million plants in it.  Each spinach plant at the time of harvest has 4-6 leaves, so choosing the middle of that range, that makes the total number of leaves in our production block around 200 million. 

    Today, sampling programs generally follow a “Z” pattern originally developed for pesticide residue sampling, which is a much different sampling challenge than microorganisms.  Along the “Z” pattern, the sampler chooses 15 points and collects 4 samples from each point for a total of 60 samples per block.  The size of the sample generally ranges from 25 grams to 100 grams per sample point or about 50 to 200 leaves.  That means a maximum number of 12,000 leaves are collected in any given field sample of 60 points.  These are generally mixed in a sample bag to form a composite sample.  From this composite, 50 to 200 leaves are selected to create a test sample.  So, in our block of 200 million potential leaves, our test comes down to evaluating 50 to 200 leaves. 

    Another way of looking at this is a commercial spinach field has an average yield of 12,000 pounds.  In our 10-acre block, that’s 120,000 pounds of harvested product.  Using the sampling program currently employed by many in our industry, we are attempting to represent that 120,000 pounds of product by sampling about three pounds of product, and then selecting a quarter of a pound of leaves from that to actually test. 

    Talk about finding a needle in a haystack!

    So why not just test more material then, Bob?

    To be sure, there many variations on the “Z”-pattern test just described.  Some are doing a “Z”-pattern test on each acre within a production block.  In the example above that would be a factor of 10 greater than just doing a single “Z” pattern on the whole 10 acres.  Others are using other patterns designed to pick up border areas as well as the center regions of a field, known as “box” or “box-X” patterns.  So while your statistics may improve by a factor of 10 or so, unfortunately you’re still in the needle in a haystack territory.  

    Remember, these contamination events are random, low frequency, and isolated. You could take a thousand samples from that same production block and only minimally increase the relative amount of product tested – and just as easily still fail to sample the exact location where the potential contamination resides. 

    And, by the way, the same sampling issues arise if you’re talking about testing finished product. Let’s say you are packing 60 to 100 bags per minute, which is standard for some products.  Simply removing five or 10 bags of product every hour or so and then making a composite sample gives you very similar statistics compared to in-field testing.

    So how exactly do you sample effectively to detect contamination?

    Well, with today’s technology, there’s really no satisfactory answer to that question.  There are new innovations on the horizon, such as environmental vacuums and other technologies that are being adapted from the Department of Defense, where screening vast areas for weaponized microorganisms has been a priority for several years.   However, given the state of sampling technology, it’s important to understand what sampling and testing can – and can’t – do. 

    Right now, the only contamination events we can feel reasonably sure to detect would be massive breakdowns in our food safety programs.  For example, if a pesticide applicator used a grossly contaminated water source to mix pesticides and then applied them to edible portions of the product, or an animal intrusion event where the animals were indeed infected with a human pathogen. Typical sampling programs might well detect this contamination, but these types of massive breakdowns have been well managed by Good Agricultural Practice programs and so have only rarely been associated with foodborne illnesses.  In other words, if a massive breakdown occurs, there are food safety programs in place to identify these issues outside of testing, and generally producers do not harvest the crop.   

    I always get back to risk-based testing. If a producer knows a risk event may have occurred like an animal intrusion, or if environmental conditions known to support pathogen survival might have been in place during production, one might increase sampling in specific locations.  Likewise, if you are producing in a field where previous potential positive samples were detected in past seasons, it may make sense to screen these fields more intensely.  It comes down to evaluating the risks associated with each production block or product run and then using the context of the physical evidence, observations, and other food safety data to better target sampling.  It means taking an active role in the sampling program and not simply putting the execution of the program on auto-pilot.

    Wow, Bob, good points to consider! Next time, we’ll explore the critical issue of raw versus finished product testing.  This is a central issue for our industry with important ramifications for supply chain logistics.

    Thank you, listeners, for joining us!

    Fresh Summit Food Safety Solutions Center

    Friday, September 24th, 2010

    Julia Stewart:

    Hello, this is PMA PR Director Julia Stewart, and welcome back to PMA’s audio blog, “Ask Dr. Bob” with PMA’s Chief Science & Technology Officer Dr. Bob Whitaker. Bob, we’re hoping all our listeners will be joining us when PMA’s 2010 Fresh Summit International Convention & Exposition convenes October 15 through 18 in Orlando. In your last post you mentioned the many workshops on food safety that will be presented at Fresh Summit. Will there be other food safety resources there as well?



    Julia, PMA has made food safety an important element of Fresh Summit for many years now, but this year we’re especially excited as we offer a high visibility resource for the topic right on the exposition floor in the form of our Food Safety Solutions Center. Located right on the show floor in booth 201, the center will be a convenient and easy way for many of our attendees to find out the latest developments in the area of food safety.



    So what exactly will the center provide?



    It’s designed to be a one-stop, interactive destination for food safety solutions. It will include educational exhibits, live demonstrations, and videos – all related to food safety technology.  The topics we will cover include packaging, traceability, processing equipment, product testing, water purification and much more. 


    PMA really wants to help industry members get answers to their most critical food safety questions, and this center is one easy way we can accomplish that. It’s being sponsored by Famous Software and we very much appreciate their support and leadership.



    So what kinds of things can visitors to the center expect to learn?



    We’ll be holding live discussions and presentations that will tackle issues such as how investing in food safety can offer ROI to your business. We’ll also cover the latest food safety innovations, considering what products and services can address specific food safety needs.


    The educational sessions we’ll conduct in the center will complement and expand on Fresh Summit’s food safety workshops that we talked about in our last post. I’m excited about the great line-up of topics and experts we have to address some of our industry’s most urgent issues right now. To give you an idea of what we have planned ….


    The session “Pass With Flying Colors: The Value of Product Testing” will be a forum to share ideas and ask those burning questions that sit at the forefront of your mind. What are the problems with sampling either raw or finished products? What are the pitfalls of product testing? If anyone has asked these types of questions, then this session is for them.


    On Sunday, “Threading the Needle: Successfully Navigating Food Safety Audits” is geared to provide answers to the key questions surrounding food safety audits. Participants can use this forum to hear first hand from experts in the industry, and get guidance and advice on topics such as costs and benefits, as well as the limitations associated with audits.


    The session “Don’t be the Weakest Link: Your Role in Traceability” will offer an update on the Produce Traceability Initiative, the value it can offer your company, and help drive the traceability decisions you make for your company today. Some of the questions we will answer include, what are the benefits behind electronic traceability? What is the driving need for industry-wide implementation of traceability measures? This Q&A session is sure to be in high demand as our experts clarify questions surrounding traceability and what it means to individual companies.


    Finally, on Monday, a session called “Experts with Answers: Learn How the Center for Produce Safety is Working for You” will explain the role that CPS is playing in answering industry’s food safety research questions and how you can get involved. We’ll also recap some of the critical research findings that were announced at CPS’s first research symposium in June. (Our listeners will remember from earlier posts that PMA founded CPS with Taylor Farms at the University of Davis back in 2007 to take leadership of industry food safety research, and that I chair the committee that leads its research program. CPS is already making a big difference to our industry.)


    Throughout the show, Industry food safety leaders and PMA experts, including myself, will be on hand in the center to lead all the Q&A sessions. Of course, another value of the center is the informal opportunities it will offer to talk with other industry members about their food safety ideas, concerns and solutions.



    It sounds like the Food Safety Solutions Center will be a great food safety resource, I’m sure our listeners will want to check it out.


    We should note that our food safety programming at Fresh Summit is made possible by the support of PMA members who contribute to our Gold Circle: Campaign for Food Safety. These members demonstrate their food safety leadership by contributing $1,000 each year above and beyond their PMA dues to support our food safety work. Their support underwrites the work of Dr. Bob’s food safety and technology team, our support of the Center for Produce Safety, new educational programs for small and local growers that we’ll talk about here soon. So thanks to our Gold Circle contributors for supporting PMA’s work. If you’d like to join our Gold Circle, you can read more on our website www.pma.com – just type “Gold Circle” into the search box on the home page.


    Listeners, if you have a food safety product or solution, we invite you to become a Food Safety Solutions Center exhibitor, sponsor or advertiser. Contact PMA’s Dot Siegfried by email at dsiegfried@pma.com.


    For more information on registering for Fresh Summit, the Food Safety Solutions Center, or any of the workshops, please log onto our website www.pma.com\freshsummit.


    Until next time, thanks for joining us!