|
New test
for contaminated sprouts
20.nov.07
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.
| 