Food Safety Magazine

PRODUCE | December 2010/January 2011

Confronting Food Safety Challenges Head-on in Produce

By Dr. Robert Whitaker

Confronting Food Safety Challenges Head-on in Produce

Produce is an integral part of a healthy diet and is touted as one of the key answers to our country’s obesity epidemic. Nevertheless, recent high-profile foodborne illness outbreaks linked to different fresh produce items have also highlighted the food safety challenges facing an industry that puts a great deal of value on its reputation for marketing naturally delicious and nutritious products.

Given the millions of pounds of produce harvested, packed, shipped and consumed each day by millions of people throughout the country without illness, we know that the frequency of pathogen contamination in produce is actually quite low. However, it only takes a single positive test identifying Salmonella or Escherichia coli in a produce item to cause serious disruption in the marketplace, precipitate a recall and put yet another dent in consumer confidence.

The highly dynamic biology of produce presents some unique and evolving challenges when it comes to food safety. Produce represents a complex chemical, physical and biological food matrix. Most obvious is how commodities vary substantially in terms of chemical composition; for example, a tomato is chemically very different from iceberg lettuce, which in turn is quite different from a green onion. Additionally, the exterior surfaces of fruits and vegetables have a vibrant microbial ecology, including many beneficial bacterial species.

The perishable nature of produce also presents challenges. Most produce must be harvested and shipped within 12 to 72 hours so it can be received in distribution centers around the country with approximately 10 days of shelf life remaining. Indeed, our entire logistics chain is built around the premise of speed, and great value is placed on getting products to market quickly. This perishable nature offers some unique challenges to the produce industry when it comes to food safety measures. Yet, this ever-resilient industry, daily battling nature and time to market the freshest products, looks to meet these food safety challenges head-on.

With those complexities in mind, some of the produce industry’s key food safety challenges include the following: which standard(s) to apply, who exactly the standards should apply to, how to provide the science that should be driving those standards and how to handle conflicts that might emerge between food safety and—for example—the industry’s commitment to environmental stewardship. Discussion of just a few of these challenges and how the industry is working to address them follows.

Defining a Single Standard
A plethora of food safety “standards” has been developed for produce over the last decade. While the number and marketing of these standards—and the audits derived from them—have benefited the industry by encouraging food safety discussions and providing food safety tools, they have also resulted in a great deal of frustration, duplication and confusion in the marketplace. The result has been cries of “audit overload” from producers and ever-increasing costs balanced against the sincere desire to improve food safety performance.

Even at a basic level, the use of the word “standard” has come to mean very different things within the produce industry, even among government regulators. Today, we have everything from Codex Alimentarius to emerging globally benchmarked standards, to proprietary third-party standards, to commodity-specific standards [e.g., California Leafy Green Marketing Agreement Good Agricultural Practices (GAPs) Metrics, tomato GAPs and melon GAPs]. All are referred to commonly as “standards,” when in fact they are very different tools designed for different purposes.

The industry and government currently have the opportunity to bring structure to defining the content of produce food safety standards. The U.S. Food and Drug Administration (FDA) is in the process of creating a food safety rule for produce with a draft rule expected in 2011. Since the FDA does not have the level of industry or operational knowledge to write produce food safety standards, the Produce Marketing Association (PMA) along with other industry groups is actively working to help the agency engage industry’s expertise. Any true standard should place equal emphasis on both the food safety content (e.g., risk assessment and management practices, etc.) and the process by which operators are audited for verification. A single defined standard would go a long way toward helping the industry focus its food safety efforts and resources.

Scalability
The increasing interest in locally grown produce imparts yet another challenge: that of ensuring small farms are as equally on the food safety bandwagon as larger ones. Some smaller-scale growers have expressed concerns over potential food safety requirements, fearing such requirements will be too costly or aren’t necessary for small-scale operations. However, a consumer who becomes ill as a result of a produce contamination event does not care whether the offending product comes from a small or large farm, from a local grower or one 3,000 miles away. The identified causes of produce-related outbreaks, including field-level contamination or contaminated inputs such as water, do not discriminate between small or large producers.

Our experience demonstrates that once growers understand the concepts of risk analysis and management, they come to understand how simple, inexpensive practices can be effective preventive controls. Often these controls are simply good operational or business practices. For example, ensuring appropriate water quality for irrigation might be as simple as a visual inspection of a well head and a good maintenance program. Regardless of size, any grower would want to maintain the working order of their well, and a weekly visual inspection should not be burdensome.

Many in the produce industry are working to provide accessible options for small and local growers. Buyers, including Sysco Corporation and Wegmans Food Markets, have implemented seminars to instruct growers on the basics of risk assessment, risk management and other food safety tools. Some state departments of agriculture or agricultural extensions perform audits at reduced costs for growers. There are also examples in central California, where third party audits have become commonplace and growers work with auditors to negotiate reduced rates for audits when farms or ranches are located together.

Product Testing Limitations
Perhaps no issue presents as big a roadblock to produce food safety as product testing. The old saying, “the devil is always in the details” applies to any discussion on pathogen testing in produce. Some of the major constraints to testing produce include the following:

Time: Our industry is rife with stories of operators who’ve suffered significant market losses because the waiting period for product testing caused product to lose its quality before it could be marketed. While rapid tests can reduce waiting periods, they are less than 100% reliable, requiring further testing that adds an additional demand on time.

Type: Testing plant tissues is more complex than testing water or equipment surfaces. Chemicals and other organic matter that can be present in or on produce frequently interfere with current test methods. For example, specific plant metabolites can interfere with polymerase chain reactions, causing “false-negative” test results.

Test: Specificity and sensitivity factors of a test must also be considered when testing fresh produce. For example, a technically inexperienced producer might opt for any one of the many off-the-shelf immunological test kits developed for Salmonella detection. While these kits are a reasonable choice for sterilized foods, they cannot be used reliably in raw produce because of the natural presence of closely related but nonpathogenic relatives of Salmonella that can cross-react with many of these tests.

Sampling: Achieving statistical significance for raw product testing at the field level or finished product testing is functionally impossible and impractical. Given the very low frequency of contamination, testing produce is analogous to trying to find a needle in a haystack.

The produce industry is becoming better educated about the limitations of product testing and the many complexities involved with it. Meanwhile, while we are waiting for the market to respond with tests and procedures that address our particular product testing needs, it is in the industry’s best interest to focus on risk assessment and management to minimize the potential for our products to become contaminated in the first place.

Research to Fill Science Gaps
Perhaps one of the most challenging aspects of food safety in the produce industry has been the absence of sound science on which to base our food safety actions. Many of the protocols that have been imposed on our industry by buyers over the past decade have been based on data extrapolated from other industries or even educated guesswork.

Recognizing the void in applicable produce-specific research, PMA founded the Center for Produce Safety (CPS) along with Taylor Farms, the University of California at Davis and the California Department of Food and Agriculture in late 2007. The center was created to define and prioritize industry research needs, fund needed research and provide the produce industry with actionable information to enhance produce safety based on those findings.

As of September 2010, CPS has invested $6.8 million in 41 produce-specific food safety research projects. CPS is already generating real-world research answers to pressing industry food safety questions as evidenced in its First Annual Research Symposium held in June 2010. Findings of CPS’ first 11 research projects were presented, followed by interactive discussions about the findings’ real-world implications and applications by panels from across the produce supply chain. (For more information on these research findings, visit cps.ucdavis.edu.)

Comprehensive Traceability
The multifaceted nature of the produce production and logistics chain also presents challenges to produce traceability. For example, a mango could be picked in Central America, packed in branded cartons, shipped by a third party to the United States, discharged into another third-party warehouse at a port, distributed to yet another third-party hauler then packed for retail and distributed to a supermarket. Every one of these touch points is a possible contributor to the integrity of the product on its way to the consumer.

Leaders in the produce industry know that we must enhance our industry’s traceability capability to reduce the scope of recalls and restore consumer confidence, as well as to promote business efficiencies. The Produce Traceability Initiative (PTI)—administered now by PMA, Canadian Produce Marketing Association, GS1 US and United Fresh Produce Association—has set a voluntary goal of chain-wide, electronic traceability by the end of 2012. Core to the PTI is the use of globally recognized GS1 standards for product identity that are well known to other product manufacturers. For more information about the PTI, visit www.producetraceability.org.

Environmental Impact
In recent years, the drive to improve food safety performance has resulted in apparent contradictions between environmental sustainability and good food safety practices. As industry-driven food safety practices have become more structured in the last few years, we have seen instances where practices instituted in the name of food safety cause concern because of negative impacts they can have on the environment and environmental sustainability.

Many factors play into this seeming contradiction between food safety and the environment. While some practices are put in place with the best of intentions (e.g., certain fencing, buffering distances), the quantitative risk and science basis for some of these practices might not be well understood. The net result has been that growers are put in the unfortunate position of trying to balance food safety against the potential environmental costs. Fruit and vegetable growers have a significant personal and financial investment in their land and are, by nature, environmentalists through and through. The land and the resources required to raise a crop are a grower’s basis for making a living—and in many cases—are the family heritage passed to future generations.

The produce industry is addressing this issue by reaching out to environmentalist groups to promote a dialogue. Additionally, as research done through the Center for Produce Safety yields results, the industry will be able to better implement targeted food safety measures with better defined parameters. Using science, risk assessment and commodity practices as an underpinning will allow us to assess the best practices to achieve both food safety goals and environmental balance.

The produce industry has evolved significantly in the past two decades, moving from a principally local bulk commodity business to a sophisticated and integrated worldwide industry. The industry’s metamorphosis has brought with it substantial challenges to food safety and, as it continues to evolve, so will the challenges and our solutions. The produce industry is all about providing healthy, nutritious products to consumers and will remain committed to seeking out and implementing the necessary tools to ensure a safe and healthy product—every bite, every time.    

Dr. Robert Whitaker has directed PMA’s food safety efforts since 2008. A recognized industry food safety leader, he was recently named to the National Advisory Committee for Microbiological Criteria for Food. He currently serves on the CPS Advisory Board and chairs CPS’ Technical Committee.

Categories: Food Types: Produce; Management: Best Practices