Battling Listeria in Produce Processing

Sanitizing. When all surfaces have been cleaned and any required verification testing completed, the final cleaning and sanitation step begins—the application of sanitizer, an EPA-approved compound that is intended to kill all bacteria remaining on the surfaces. Many ready-to-eat facilities use a three-step process—disinfection, rinse, sanitize—for greater efficacy. A sanitizer is applied at a higher concentration, rinsing happens after appropriate contact time, and a no-rinse concentration is applied prior to starting production.

Sanitizers, applied at a “no-rinse” concentration, should be drained but not rinsed off the surfaces prior to the start of processing. Because some produce items can be damaged upon contact with certain sanitizers, it is essential that sanitizers be compatible with the products being processed. Furthermore, rotating, or changing, sanitizers on a regular basis is recommended to provide an additional challenge to resident microbes.

The steps described above can be applied to all produce processing facilities, whether they run conventional or organic products. Differences occur at the sanitation step, where the final sanitizer must be one that is approved for organic production.

Listeria represents a growing challenge for produce processors, who are concerned about both their brand and their consumers’ health. There is no single “silver bullet” that can prevent Listeria contamination on fresh produce. However, a robust cleaning and sanitation program with multiple interventions can allow effective control of Listeria in produce processing facilities.

Dr. Owens is the director of technical services at Birko in Henderson, Colo. Reach him at 800-525-0476.