It’s Not Easy Bein’ a Green: Tips on Optimizing Leafy Green Safety

What can be a problem for an amphibian also pertains to produce. Consider this: The famous muppet Kermit the Frog appears to have it all—notoriety, popularity, and tremendous professional success. Yet, he sings, “It’s not easy bein’ green.”

Like Kermit, lettuce and spinach seem to have it all—nutritional notoriety, popularity, and booming sales. On average, according to the United Fresh Produce Association (UFPA; Washington, D.C.), 5 million bags of leafy greens are produced in the United States each day, and some 2 billion bags are sold annually. But in recent years, it hasn’t been easy to be a leafy green. The salad staples have gotten a bad rap on several occasions, and they’ve even been deadly, all because of a pathogen with killer capabilities.

Since 1995, some 22 outbreaks of foodborne illness caused by Escheria coli O157:H7 have been associated with consumption of fresh or fresh-cut lettuce and two with pre-washed spinach, according to the U.S. Food and Drug Administration (FDA). What was arguably the most widespread, dramatic, and highly publicized of these incidents occurred in 2006, when an outbreak of E. coli O157:H7 was linked to pre-washed spinach. Soon after, two outbreaks traced to the consumption of pre-washed iceberg lettuce at chain restaurants occurred.

Since the 2006 outbreaks, the leafy greens industry has developed and implemented extensive new food safety standards, metrics, and compliance programs, says David Gombas, PhD, UFPA’s senior vice president of food safety and technology. “In order to continue to improve the science that is the basis for these standards and programs, we must first identify the industry’s most acute research needs,” Dr. Gombas says. “That’s why, in September 2007, United Fresh hosted the first International Lettuce and Leafy Greens Food Safety Research Conference, which brought together U.S. and international academic scientists, state and federal regulators, and industry representatives to identify those essential research needs.”

These stakeholders were charged with developing a prioritized list of research needs to address the issue of E. coli O157:H7, Salmonella, and other human pathogens found in and on lettuce and leafy greens.

While some speculate that the 2006 crisis was attributable to water, cattle manure, and wildlife manure contaminated with E. coli O157:H7 in the vicinity of California spinach fields, the source of contamination was never definitively determined, according to the California Food Emergency Response Team, a collaboration of the California Department of Public Health (CDPH) and the FDA.

Farm to Fork Approach

“To minimize the risks associated with leafy greens, you have to scrutinize every step from farm to fork, and contaminants have to be controlled better than one in two billion bags per year,” Dr. Gombas says.

Under the authority of the California Department of Food and Agriculture (CDFA), a Leafy Green Products Handler Marketing Agreement (LGMA) was developed and implemented on April 2, 2007. The LGMA specifies that CDFA staff may conduct periodic inspections of leafy green handlers who are signatories to the LGMA to verify compliance with good agricultural practices (GAPs) developed by industry, reviewed by the CDPH and FDA, and referenced in the LGMA at www.caleafygreens.ca.gov.

The proactive response to produce safety demonstrated by Natural Selection Foods (San Juan Bautista, Calif.), the firm implicated in the 2006 outbreak, is an example of management commitment, says Gale Prince, a food safety professional with 40 years experience in the retail food industry. He cites the company’s application of the latest science to the production of ready-to-eat produce as an example of produce safety programs of the future.

“Their program is built on rigorous field-by-field risk assessments of the growing environment and in further handling and processing,” Prince says. “The hold and test programs for raw materials and finished products at various points verify the efficacy of the upstream food safety measures put forth in” good agricultural practices and good manufacturing practices.

Expert Panel on Produce

Following the alarming events of 2006, Dr. Gombas served on a panel of 14 scientists with special expertise in the microbial safety of fresh produce, convened to review recently published research and current recommendations on the use and handling of packaged leafy green salads. Targeting three audiences—food service and restaurant operators, regulatory agencies with oversight over food facilities, and consumers—the panel developed guidelines for handling pre-washed bagged salads.