kernels are caused by internal-feeding grain insects. If more than 32 damaged
kernels are found per 100 grams of wheat, the value of the grain is greatly
decreased. Click the image for more information about it.
How Wheat Kernels Sing Is a Sign of
Their Quality By Erin Peabody March
How do you find the bad seeds in the bunch? According to
Pearson, a scientist with the Agricultural Research Service (ARS), you listen very closely.
Pearson--whos an agricultural engineer at the agencys
Marketing and Production Research Center in Manhattan, Kan.--has developed
an acoustics-based sorter that can distinguish between clean wheat
kernels and those that have been nibbled on and spoiled by insects.
The idea behind the novel technology is simple. A wheat kernel
thats whole and intact will make a slightly different, high-pitched
ping when striking a steel plate than the sound made by a kernel
thats been tunneled through by an insect.
Lesser grain borers
develop and feed inside wheat kernels. Click the image for more information
Because individual kernels are so small, lightweight and hard, any
acoustic energy they emit is inaudible to human ears. So, Pearson made sure to
outfit his sorting system with a special microphone that can pick up
ultra-sonic sounds at exceptionally high frequencies.
After assessing the kernels acoustic qualities, the sorter will
shunt the insect-damaged wheat kernels from a random sample into one bin, and
send acceptable kernels into another. It can even pinpoint kernels
with tiny insect larvae hiding inside them, a feat that, for grain inspectors,
is like trying to find a needle in a haystack.
Every year, more than $1.5 billion worth of U.S. wheat and other
grains must be discarded or downgraded because of post-harvest damage by insect
pests. Despite preventive measures, the pestsranging from moth larvae to
small flour beetlesstill manage to find their way into grain storage
Now, most grain inspectors must laboriously sift through samples of
grain by hand, relying on the naked eye to spot wheat kernels that have been
spoiled by insects. It can take more than 20 minutes to examine a 100-gram
sample, or one weighing about one-quarter of a pound.
Pearsons sorter can analyze the same sample in about 75 seconds,
or at a rate of 40 kernels per second. And it successfully detects damaged
kernels 87 percent of the time.
The technologywhich would undoubtedly lead to more accurate
estimates of insect damage in wheat loadsis now ready for a
private-sector partner to help bring it to market.
ARS is the U.S. Department of
Agricultures chief, scientific research agency.