New Test for Contaminated Sprouts 20

New test for contaminated sprouts

Ontario Farmer
Jim Romahn

The sprouts industry has, according to this story, a new method for testing for food-poisoning bacteria.

The story says that the new test is much faster and broader because the samples are taken from the irrigation water used to grow the sprouts, then concentrated and tested. The standard alternative approach has been to take a sample of irrigation water and multiply the bacteria populations to the point where tests can be run for harmful strains.

Despite the high risk and these test improvements, so far no commercial sprouts growers have picked up on the research by a team at the University of Guelph.

Student Rachael McEgan was cited as saying the only commercial interest so far has come from a lettuce grower in Florida.

She was at a poster presentation of the research during the recently-held 49th annual meeting of the Ontario Food Protection Association at Mississauga.

McEgan worked with a colleague, T.J. Fu, under the leadership of professor Keith Warriner.

McEgan said their test provides results within six to eight hours. It’s broader because it involves a larger volume of water.

Two years ago there was a major outbreak of food poisoning in Ontario that was traced to mung bean sprouts. Alfalfa sprouts have been fingered in so many outbreaks that food safety specialist Dr. Doug Powell of Kansas State University called them one of the riskiest foods on the market.



Note from the SproutNet

Although this research is very promising, according to Dr Fu, as of this writing there are no commercially available “concentrators” for food sampling and testing. There are a number of tangential flow filtration (TFF) systems that are commonly used by the pharmaceutical industry. Depending on the applications, there are units that can process small samples (less than 100 ml) and there are also units that can process very large volumes of fluids (e.g., 10,000 L).  None of them have the capacity in the range of 10 L, with a detection limit of 1-10 cfu/10 L. which is what the commercial sprout production industry needs.


The concentrator they used can be found in

“Interventions to Improve Food Safety of Sprouted Seeds”, a PowerPoint Presentation by Keith Warriner for British Columbia’s Premier Food Safety Conference – October 18, 2007.