The nonchlorine-based sanitizer, which contains levulinic acid and sodium dodecyl, can be used by vegetable farmers as a preharvest spray to control diseases such as Salmonella and E. coli.
While most farmers rely on postharvest washing to reduce the risk of foodborne pathogens, the new study suggests that applying sanitizers to produce while it is still in the field is an effective solution that can also lower labor costs.
“Tomatoes are grown in environments in which Salmonella may reside as a result of fecal contamination from animals, such as livestock, wildlife and reptiles,” explained the study authors.
Initially, Zhao’s team was going to investigate the use of a postharvest wash solution made of two food additives approved by the U.S. Food and Drug Administration.
Bill Brim of Lewis Taylor Farms suggested that the study should be designed using the solution in a preharvest spray.
While producers commonly use chlorine-based disinfectants to treat produce postharvest, the preharvest application of bactericides is not a common practice, said Zhao.
Previous studies showed that the combination of levulinic acid and sodium dodecyl sulfate substantially reduced both Salmonella and E. coli on romaine lettuce without adversely affecting lettuce quality.
Zhao wanted to test the solution’s effectiveness on contaminated tomato plants.
The tomato plants were then separated into three groups and were treated in the following ways: with a test solution levulinic acid and sodium dodecyl sulfate, with acidified chlorine as a control, or with only tap water.
The studies showed that the test solution significantly reduced the populations of inoculated Shiga toxin-producing E. coli, Salmonella, and L. monocytogenes on tomato plants.