Antimicrobial Wash Reduces Health Risks in Fresh Produce

By Dennis O'Brien
January 20, 2016

An Agricultural Research Service (ARS) scientist in Wyndmoor, Pennsylvania, and his collaborators have developed an antimicrobial wash that reduces the risk of foodborne pathogens contaminating fresh produce.

Joshua Gurtler and scientists at NatureSeal Inc. have found that a combination of lactic acid, fruit acids, and hydrogen peroxide can be used in a produce rinse for commercial food distributors. NatureSeal, based in Westport, Connecticut, already markets an anti-browning wash developed by another ARS team in the 1990's for sliced apples and 18 other types of produce.

E. coli, Listeria, Salmonella and other foodborne pathogens sicken approximately 1 in 6 Americans (48 million people) each year. A recent U.S. outbreak of Salmonella associated with cucumbers sickened over 765 people in 36 states and killed 4.

First Step+ 10 is designed to reduce those numbers, and is expected to be used in the commercial flumes and rinse tanks that wash fresh produce, Gurtler says. The ingredients are all classified as Generally Recognized as Safe (GRAS) by the U.S. Food and Drug Administration (FDA). The wash also has been approved for use in Canada; is U.S. Department of Agriculture (USDA) certified organic; is biodegradable; and does not affect the taste, texture, smell, or appearance of produce.

To save water, some food processors reuse wash water, a practice that can contaminate produce in subsequent washes. Along with reducing the risk of contamination, the new rinse will cut back on waste water because processors won't have to replace water in their tanks as frequently.

To test First Step+ 10, Gurtler inoculated fresh cut apples, baby spinach, cantaloupe rind, and cherry tomatoes with highly resistant outbreak strains of E. coli O157:H7, Listeria, and Salmonella. He soaked them in the wash for 5 minutes and then measured pathogen levels in the wash water and on the produce. The antimicrobial wash reduced pathogen levels on the produce by 99.99 percent. It also rid the wash water of 100 percent of pathogens, making it safer to reuse.

Along with securing FDA approval, Gurtler and his collaborators at NatureSeal have filed a patent application and presented findings at scientific meetings.

ARS is USDA's chief intramural scientific research agency.

Read more about this work in the January 2016 issue of AgResearch.