New effective product for vegetable washwater
By University of Idaho
By University of Idaho
June 30, 2008 Boise, ID — Research
conducted at the University of Idaho and Washington State University
indicate that a new fruit and vegetable wash can decrease the number of
organisms in washwater.
That could reduce the potential for cross-contamination within the water by such “gram-negative” bacteria as Salmonella and E. coli O157:H7.
The product, sold commercially as FIT Fruit and Vegetable Wash, not only proved more effective than the commonly used chlorine dioxide but is made from ingredients like citric acid and distilled grapefruit oil that are generally regarded as safe.
Chlorine dioxide, whose use in food plants can put workers at risk, was compromised by soils and plant debris in the washwater and killed only 90 per cent of the target organisms in the food plant and followup laboratory studies. By contrast, FIT killed 99.9999 per cent, according to associate professor of food science Dong-Hyun Kang of Washington State University.
“If you had a million bacteria, you would have one left,” explained Kang.
The research — unusual because part of it was conducted under real-world conditions in an Idaho freshpack potato operation — will be published by the Journal of Food Science in August and is currently available here.
University of Idaho Extension food scientist Jeff Kronenberg said the researchers chose potatoes for their study because their dirt-laden washwater poses the greatest challenge to products designed to control microbial contamination — not because of any food-safety threat potatoes pose.
“We have historically had zero problems with food-borne diseases in potatoes that are sold in grocery stores and restaurants because they’re cooked,” said Kronenberg.
Kronenberg believes FIT should be further investigated for fresh produce that has been associated with food-borne illness — including lettuce, spinach, tomatoes, cilantro, parsley and other leafy vegetables — where it is has the potential to save lives.
According to Kang, most food-processing firms cleanse their produce in flumes that operate as aquatic conveyor belts.
“If a pathogen is introduced in the washwater, it will grow and continuously contaminate the new produce,” he said.
With 15 years of experience, Kang has found it “very, very difficult” to control disease-causing organisms in flume water and said he “didn’t expect this kind of reduction. I’m really happy to see it.”
WSU research technologist Peter Gray agreed, noting that the bacteria were “knocked down below the detection limit almost instantaneously” in the FIT treatments.