Your Eggs Safer--in a Flash
You've heard of lightning in a bottle, but how about lightning in a box?
That's the effect that Agricultural Research Service (ARS) scientists
create when they look for very small cracks in chicken eggs. Nobody wants
to buy a carton of eggs only to find that some are cracked. But tiny cracks,
called micro-cracks, can be so small that sometimes even an experienced
egg inspector's eye misses them at the processing plant. Unfortunately,
the micro-cracks grow over time, and by the time the eggs reach the supermarket,
those cracks can be pretty big.
The shell protects the egg from contamination, so detecting cracks is
important. Fortunately, eggs are carefully inspected in commercial plants
before consumers buy them.
But, as we said earlier, even the most experienced inspectors, or "graders,"
can miss a micro-crack. So the egg industry could really use a better
way to detect micro-cracks--one that is simple and inexpensive, and works
with large batches of eggs. ARS scientists found a solution.
The scientists built a device that helps find those hard-to-see cracks.
The scientists are food technologist Deana Jones at the ARS Egg Safety
and Quality Research Unit; engineers Kurt Lawrence, Seung Chul Yoon and
Bosoon Park, image analyst Jerry Heitschmidt, and technician Allan Savage
at the Quality and Safety Assessment Research Unit. Both research units
are part of the Richard B. Russell Research Center in Athens, Georgia.
ARS has filed an application for the technology. You can earn more from
the ARS Science For Kids story "I
Am an Inventor!" A patent is a short write-up that describes
an invention. A patent includes background information, drawings, and
models or pictures of the invention (roll-over definition).
Lawrence's technology uses a pressure chamber, specialized camera, and
computer program to create a lightning-like flash that makes even the
tiniest cracks obvious. The chamber is a sealed container that uses pressurized
gas to "suck" the eggshell gently outward. An early version
of the chamber was built for a single egg, but the scientist quickly expanded
it to a 15-egg chamber, and then to a 20-egg chamber. To test the chamber,
Lawrence got 1,000 white-shell table eggs from a nearby egg processing
facility, brought them to the laboratory, and let them reach room temperature
to copy real processing conditions.
Many of the experimental eggs were rolled around to cause micro-cracks,
then were immediately examined by human graders and scored as either intact
or cracked. The eggs were later placed in the chamber for imaging and
re-graded for comparison. The results were surprising: 99.6 percent accuracy
overall. "In comparison, the professional human graders had an overall
accuracy of 94.2 percent on these hard-to-see micro-cracked eggs,"
Lawrence says. "These results are much better than anyone had achieved
"This could very well give egg graders a tool they can use to consistently
identify cracked eggs for removal from the processing line while not removing
intact eggs," Lawrence says.
Research Service, Information Staff
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