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Detecting Possible E. coli
Contamination on Fruit and Produce By
September 30, 2002
The chance of fecal bacteria contaminating fresh produce or
fruit juices could become nil when fruit- and produce-packing plants have a
completely automated food safety inspection system installed in the near
Yud-Ren Chen, an agricultural engineer with the
Agricultural Research Service's
Sensing Laboratory in Beltsville, Md., is leading a group to develop
"machine-vision" systems to detect contamination the human eye can't see. This
would prevent Escherichia coli O157:H7 from tainting apple cider and
juices made from apples and other fruits. This E. coli strain infects
people who drink contaminated, unpasteurized cider or juices.
Chen is starting with apples, but he expects the system to work
with all fruits and produce. His on-line system would direct a camera to take
three spectral images of each apple through different color filters. A computer
would then analyze the spectral images to detect the telltale signatures of
fecal contamination or fly specks, as well as of fungi, rot or other
One of Chen's team members, biophysicist Moon Kim, brought his
expertise in remote sensing of vegetation to ARS from the
National Aeronautics and Space
Administration. To detect fecal contamination, he is still sensing
photosynthetic pigments from plants. But now he's working barely two feet from
his targets, rather than from sensors aboard airplanes or satellites.
Apple packinghouses currently have automated ways to sort for
sizes and colors. When Chen's system is commercialized, it would likely be
merged with those sorting systems, as well as with others in the pipeline.
ARS is the
U.S. Department of Agriculture's chief
scientific research agency.