ARS Works To Enhance Food Safety

Enhancing Food Safety

Researcher Ching-Hsing Liao developed and tested a method that pits beneficial bacteria against potentially harmful ones. Bell peppers were dipped in solutions of water containing some of these beneficial bacteria. One bacterium, Pseudomonas fluorescens (Pf) 2-79, was particularly effective. 

In 2006, E. coli nearly devastated spinach growers. This year, a Salmonella scare almost ruined the season for tomato growers. With global concern over U.S. food scares, many fear that the situation has reached critical mass; but a new food safety treatment developed by Ching-Hsing Liao, a microbiologist for USDA’s Agricultural Research Service (ARS), may help.

Liao developed and tested a method that pits beneficial bacteria against potentially harmful ones. The beneficial bacteria inhibit the growth of pathogens that survive initial physical or chemical attempts to remove them from fresh produce, thus increasing the effectiveness of conventional produce sanitation methods.

“Biological treatment as demonstrated in our study can only be used as a complement to the conventional treatment,” Liao says. “Biological treatment can only suppress the growth of the pathogen but does not kill the pathogen. If the initial number of pathogens on naturally contaminated produce is high, application of biocontrol by itself would be able to eliminate or reduce the pathogen number to a non-harmful level; however it cannot replace conventional chemical or physical treatments.”

Liao identified three beneficial antagonists for use in food safety intervention. He dipped bell peppers in solutions of water containing beneficial antagonists and examined the effect on surface pathogens including Salmonella and E. coli.

An Effective Solution

One bacterium, Pseudomonas fluorescens (Pf) 2-79, was particularly effective. Dipping peppers in a Pf 2-79 solution for two minutes halted pathogen multiplication almost entirely.

“Conventional treatment either by chemicals or physical forces can only reduce 90% to 99% of the pathogens on produce,” Liao says. “Pathogens that survive the treatment can renew the growth on produce to a level capable of causing illness. If beneficial bacteria or biological control agents are applied following chemical or physical treatment, they will suppress the growth of survivor pathogens.”

On untreated peppers, pathogen populations multiplied 100,000 times when stored at 68°F for two days, but treating peppers with Pf 2-79 suppressed pathogen growth.

“Since the number of Pf 2-49 introduced onto produce is at a level much higher than the number of pathogen on naturally contaminated produce or on produce that has received other intervention treatment, robust proliferation of Pf 2-79 on inoculated produce is expected to deplete all the space or nutrients required for the growth of pathogens, or competitive exclusion,” says Liao.

The Pf 2-79 dip also suppressed the growth of spoilage or soft-rotting bacteria on bell pepper and reduced the incidence of soft rot, which indicates the treatment would not only improve the safety but also the quality of produce, according to Liao.

Because Pf 2-79 is easy to grow, the cost would be affordable once Liao and his colleagues can prove the economic benefit, he says. The treatment would be best done at produce packaging or processing plants by adding powder or liquid form of Pf 2-79 directly into a water wash tank or spraying produce with the solution, according to Liao. A regulatory approval through FDA or EPA may be required before the strain of Pf 2-79 can be used for field and commercial testing, he says.

Liao and his colleagues plan to validate the research on a larger scale, as well as identify additional bacterial strains that could be used with Pf 2-79 to further improve produce safety and quality.

“We are in the process of evaluating if mass application of Pf 2-79 would cause any sensory or flavor/aroma change on treated produce, although no indication of such undesirable effect has been observed so far,” Liao says.

Leave a Reply

Featured Stories
Wildflower planting to support bees on a Michigan blueberry farm. (Photo Credit: Emily May)
Fruits
December 2, 2016
Food Company Invests $4 Million In Pollinator Habitat
General Mills, Natural Resources Conservation Service, and the Xerces Society announce multi-year commitment to help pollinators prosper. Read More
(USPP#26,610) A yellow clingstone nectarine that ripens between June 16 to 26. The fruit is very large, firm, has great flavor and has good storage and shipping qualities. The tree is large and vigorous and produces an excellent crop. Requires approximately 450 hours of chill.
Fruits
December 2, 2016
The Burchell Nursery 2017 Variety Showcase [Slideshow]
The Burchell Nursery, Inc., in Oakdale, CA, offers a new self-fertile almond, an early-season nectarine, and a late-season peach. Read More
Grower Jonathan Brown of Bethel Farms inspects his citrus grove.
Citrus
December 2, 2016
Citrus Survey Shows Florida Growers Are Bully For Bactericides
Growers are betting unique crop protection tools will bridge the gap to bigger HLB solutions. Read More
Photo credit: USDA
Citrus
December 1, 2016
Bio Huma Netics App Now Released For Android Smart Phones
App includes foliar application calculators and ability to save application data. Read More
Low-volume center pivot irrigation at Jones Potato Farm in Florida
Farm Management
December 1, 2016
Florida Farmers Are Good For The Environment
All three recipients of this year’s Agricultural-Environmental Leadership Awards are proof of agriculture’s longstanding commitment to conserving the Sunshine State's precious natural resources. Read More
Premier™ Honeycrisp was discovered by the growers at Mount Ridge Fruit Farms in Adams County, PA. Premier™ is a complete tree sport of Honeycrisp that matures three weeks earlier. From what we’ve observed, Premier™ shares many of the same attributes of the original Honeycrisp and should not be considered a red strain. USPP#24,833 (DAS 10 CLTV.)
Fruits
December 1, 2016
Adams County Nursery 2017 Variety Showcase [Slideshow]
Adams County Nursery, Inc., in Aspers, PA, offers a Honeycrisp strain that ripens three weeks before the original variety. Read More
CBS This Morning citrus story interview
Citrus
December 1, 2016
Telling The Story Of Florida Citrus More Important Now Than Ever
HLB forces an emphasis on grassroots efforts to paint a positive picture. Read More
2016 Florida Ag Expo tomato variety field tour
CEU Series
December 1, 2016
CEU Series: Back A United Front To Fight And Defeat Pests
Coordination and integration are key factors to any successful crop protection battle plan. Read More
This watermelon seedling is showing Fusarium wilt symptoms. The first symptom that appears on infected plants is wilt in a single leaf or a single vine.
Photo credit: Kathryne Everts
Crop Protection
November 30, 2016
The Effect Of Soil Fertility On Fusarium Wilt In Watermelon
Ongoing research sheds light on the role soil health plays in the severity of the deadly pathogen. Read More
Produce case at Hopcott
Fruits
November 30, 2016
‘Dirty Dozen’ — Dirtier Than You Think [Opinion]
Find out how the Environmental Working Group is making money off its annual list that slams conventional produce. Read More
The Latest
Fruits
December 2, 2016
Food Company Invests $4 Million In Polli…
General Mills, Natural Resources Conservation Service, and the Xerces Society announce multi-year commitment to help pollinators prosper. Read More
Fruits
December 2, 2016
The Burchell Nursery 2017 Variety Showca…
The Burchell Nursery, Inc., in Oakdale, CA, offers a new self-fertile almond, an early-season nectarine, and a late-season peach. Read More
Citrus
December 2, 2016
Citrus Survey Shows Florida Growers Are …
Growers are betting unique crop protection tools will bridge the gap to bigger HLB solutions. Read More
Citrus
December 1, 2016
Bio Huma Netics App Now Released For And…
App includes foliar application calculators and ability to save application data. Read More
Farm Management
December 1, 2016
Florida Farmers Are Good For The Environ…
All three recipients of this year’s Agricultural-Environmental Leadership Awards are proof of agriculture’s longstanding commitment to conserving the Sunshine State's precious natural resources. Read More
Fruits
December 1, 2016
Adams County Nursery 2017 Variety Showca…
Adams County Nursery, Inc., in Aspers, PA, offers a Honeycrisp strain that ripens three weeks before the original variety. Read More
Citrus
December 1, 2016
Telling The Story Of Florida Citrus More…
HLB forces an emphasis on grassroots efforts to paint a positive picture. Read More
CEU Series
December 1, 2016
CEU Series: Back A United Front To Fight…
Coordination and integration are key factors to any successful crop protection battle plan. Read More
Crop Protection
November 30, 2016
The Effect Of Soil Fertility On Fusarium…
Ongoing research sheds light on the role soil health plays in the severity of the deadly pathogen. Read More
Fruits
November 30, 2016
‘Dirty Dozen’ — Dirtier Than You Think […
Find out how the Environmental Working Group is making money off its annual list that slams conventional produce. Read More
Vegetables
November 30, 2016
Harris Moran Seed Company 2016 Vegetable…
For more information, contact Harris Moran Seed Company: 260 Cousteau Place, Suite 210, Davis, CA 95618 800-320-4672: WEBSITE hmclause.com FAX: Read More
GenNext Growers
November 30, 2016
Virtual Conference Designed For New, Beg…
National Farmers Union to present a conference that is entirely web-based. Read More
Insect & Disease Update
November 30, 2016
Florida’s Top Citrus Growers Sound…
Fighting pyllids, better weather, and new varieties will hopefully bring improved yields. Read More
More Vegetables
November 30, 2016
Keys To Successful Bell Pepper Productio…
Proper water management and pruning strategies can help improve yields. Read More
More Vegetables
November 29, 2016
Clifton Seed Company 2016 Vegetable Vari…
For more information, contact Clifton Seed Company P.O. Box 206, Faison, NC 28341 910-267-2690; CliftonSeed.com FAX 910-267-2692; [email protected] Read More
Fruits
November 29, 2016
New Precooler Boasts Shorter Times, Grea…
Global Cooling Inc. has introduced a new portable precooler – the Jet-Ready Precooler. The Jet Precooler is a forced air Read More
Fruits
November 29, 2016
Van Well Nursery Celebrates 70th Anniver…
Nursery known for ‘Red Delicious,’ ‘Fuji,’ ‘Gala’ sports making a name for itself in the 21st century. Read More
Citrus
November 29, 2016
Saving California Citrus Means Thinking …
Saving the California citrus industry from the incurable disease Huanglongbing will take a creative multi-pronged effort. Read More