ANAHEIM, Calif. — Wash water may not be the sexiest of topics, but it has moved into the spotlight after it was associated with several recent food safety illness outbreaks.
Because of its importance and recent evolution, the Produce Marketing Association devoted two educational sessions, including a panel discussion, to the topic at the 2012 Fresh Summit, Oct. 26.
“We’ve come from just adding sanitizer and maybe controlling your pH to now kind of rethinking this, thinking about validating what we’re doing and then going on to verify it,” said Bob Whitaker, PMA chief science and technology officer.
Validation and verification are different, although they’re often mistakenly used interchangeably, he said.
Validation is to prove, using science, that a process or design works. It also involves setting operation parameters.
Verification involves routine sampling or testing to ensure the system is working as designed or within those parameters.
But minimizing contamination in water should be part of a larger program that begins with variety selection and continues throughout the entire food chain, said Trevor Suslow, a University of California-Davis, Extension research specialist of preharvest to postharvest food safety.
Microbial contamination in the field is typically isolated and localized, Suslow said, yet “water has the greatest potential to redistribute that small localized contamination to become a large contamination.”
The goal is to reduce microbial risks beforehand, then maintain proper sanitizer levels in the water to minimize the chances of cross contamination.
Water used in hydrocooling, dump tanks, flotation tanks, and spray lines and brush beds is also of concern.
“This is the one spot in the process — a tunnel spot in the process — whether it’s cooling or your washing process in a plant that you have a moment in time to control or potentially exacerbate the problem,” said Drew McDonald, senior vice president of quality and food safety for Danaco Solutions LLC, Salinas, Calif.
What works for one processor or packer may not work for another because of equipment design, commodity differences and water flow, just to name a few variables.
Walter Ram, vice president of food safety for The Giumarra Cos., Los Angeles, suggested that biological considerations be added to mechanical needs during equipment design.
Although Wal-Mart officials acknowledge that the vast majority of U.S.-grown produce is safe, they continue to work to improve good agricultural practices standards and process controls, said Natalie Dyenson, senior director of supplier food safety for Wal-Mart, Bentonville, Ark.
Where she says she sees a void is among small- and medium-sized farms that may not have the technological expertise on staff to validate different processes.