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

CitrusBe Willing To Take A ‘Wild Turkey’ Approach To Farm Fixes [Opinion]
November 27, 2014
Editor Frank Giles says Florida Grower will be stepping up to the bully pulpit in 2015 addressing topics that impact the industry the most. Read More
CitrusNew Partnership To Expand ‘Fresh From Florida’ Footprint In Taiwan
November 26, 2014
Latest deal puts exclamation point on successful Asia marketing campaign. Read More
Insect & Disease UpdateCalifornia OKs Asian Citrus Psyllid Insecticide
November 26, 2014
Agriphar Crop Solutions’ Micromite 80WGS is also effective on several other citrus pests. Read More
VegetablesAmerican Takii Presents Its Latest Vegetable Varieties
November 26, 2014
For more information, contact: American Takii 301 Natividad Rd. Salinas, CA 93906 831-443-4901; fax: 831-443-3976 takii.com Read More
FruitsWet December Predicted For Parched California
November 25, 2014
National Weather Service says above-normal precipitation expected; it may continue through the winter in central and southern parts of the Golden State. Read More
Apples & PearsEPA Approves Three New Moth Mating Disruption Products
November 25, 2014
Codling moth and oriental fruit moth are targeted by apple and pear growers. Read More
VegetablesSakata Hosts Annual Fall Field Trials
November 25, 2014
Growers and dealer partners gather to see new varieties at the company's South Florida field station. Read More
VegetablesStokes Seeds Presents Their Latest Vegetable Varieties
November 25, 2014
For more information, contact: Stokes Seeds P.O. Box 548 Buffalo, NY 14240-0548 800-263-7233; fax: 800-272-5560 stokesseeds.com Read More
VegetablesAbbott & Cobb Presents Their Latest Vegetable Varieties
November 25, 2014
For more information, contact: Abbott & Cobb P.O. Box 307 Feasterville, PA 19053 800-245-SEED; fax:215-245-9043 abbotcobb.com Read More
VegetablesVariety Trials 2014: Rupp Seeds
November 25, 2014
Check out new pumpkins weighing between 18 and 20 pounds as well as new powdery-mildew tolerant butternut squash hybrids. Read More

The Latest

CitrusBe Willing To Take A ‘Wild Turkey’ Approach…
November 27, 2014
Editor Frank Giles says Florida Grower will be stepping up to the bully pulpit in 2015 addressing topics that impact the industry the most. Read More
CitrusNew Partnership To Expand ‘Fresh From Florida’ Foot…
November 26, 2014
Latest deal puts exclamation point on successful Asia marketing campaign. Read More
Insect & Disease UpdateCalifornia OKs Asian Citrus Psyllid Insecticide
November 26, 2014
Agriphar Crop Solutions’ Micromite 80WGS is also effective on several other citrus pests. Read More
VegetablesAmerican Takii Presents Its Latest Vegetable Varieties
November 26, 2014
For more information, contact: American Takii 301 Natividad Rd. Salinas, CA 93906 831-443-4901; fax: 831-443-3976 takii.com Read More
FruitsWet December Predicted For Parched California
November 25, 2014
National Weather Service says above-normal precipitation expected; it may continue through the winter in central and southern parts of the Golden State. Read More
Apples & PearsEPA Approves Three New Moth Mating Disruption Products
November 25, 2014
Codling moth and oriental fruit moth are targeted by apple and pear growers. Read More
VegetablesSakata Hosts Annual Fall Field Trials
November 25, 2014
Growers and dealer partners gather to see new varieties at the company's South Florida field station. Read More
VegetablesStokes Seeds Presents Their Latest Vegetable Varieties
November 25, 2014
For more information, contact: Stokes Seeds P.O. Box 548 Buffalo, NY 14240-0548 800-263-7233; fax: 800-272-5560 stokesseeds.com Read More
VegetablesAbbott & Cobb Presents Their Latest Vegetable Varie…
November 25, 2014
For more information, contact: Abbott & Cobb P.O. Box 307 Feasterville, PA 19053 800-245-SEED; fax:215-245-9043 abbotcobb.com Read More
VegetablesVariety Trials 2014: Rupp Seeds
November 25, 2014
Check out new pumpkins weighing between 18 and 20 pounds as well as new powdery-mildew tolerant butternut squash hybrids. Read More
Food SafetyMultistate Salmonella Outbreak Linked To Bean Sprouts
November 25, 2014
FDA and the Centers for Disease Control and Prevention along with state and local officials continue to investigate the food-borne illness outbreak. Read More
Insect & Disease UpdateCitrus Survey: New Management Techniques Trending
November 25, 2014
Growers widen their tactical approach to survive HLB. Read More
FruitsFruitGrowerConnect Brings Buyers And Sellers Together […
November 25, 2014
Suppliers and growers got down to business in San Diego discussing current needs, solutions, and ways to increase efficiencies on the farm. Read More
Vegetables15 Must Have Carrot Varieties [Slideshow]
November 24, 2014
Browse the slideshow for information on 13 carrot varieties to add to your collection. Read More
CitrusReasons Aplenty Florida Growers Should Feel Good Going …
November 24, 2014
Thanks to recent industry achievements, the next 12-month period is shaping up to be a year to remember --- fondly. Read More
BerriesSuspected Borer Could Be Big Bother To Florida Blueberr…
November 24, 2014
Producers warned to be on the lookout as scientists probe samples. Read More
NutsWatch Your Almonds’ Salt Intake
November 24, 2014
Because of the current California drought, almond growers must pay extra attention to soil salinity. Read More
Varieties & RootstocksHelp On The Way Citrus Growers Can Truly Tap Into
November 24, 2014
Demand for inventory to rise as USDA’s Tree Assistance Program pushes new plantings. Read More