New Instrument Helps in Determining Wheat QualityBy
An automated system to identify wheat classes, characteristics and
defects--including kernels damaged by diseases such as karnal bunt or
scab--could help grain inspectors verify whether wheat is suitable for
export. The first commercial prototype of the system is being
demonstrated this week at the annual meeting of the American
Association of Cereal Chemists, held in San Diego, Calif., October
Karnal bunt is a wheat fungus recently found in areas of the
southwest U.S. If samples of wheat contain "bunted kernels"--those
infected with karnal bunt-- countries without the disease may not
import the infected wheat. So it's critical that uninfected wheat can
be certified free of karnal bunt.
Currently, bulk wheat samples are visually examined for bunted
kernels. But grain inspectors would need to check only a few wheat
kernels with a new instrument designed by
Agricultural Research Service
scientists and engineers with Perten Instruments North America,
Springfield, Ill. The instrument detects either common or karnal bunt
and sorts suspect kernels. A positive result would signal the
inspector to verify visually whether the suspect kernel is infected
with karnal bunt.
In preliminary tests at ARS' Grain
Marketing and Production Research Center in Manhattan, Kan., the
instrument correctly identified 93 percent of all bunted kernels.
The instrument combines near-infrared technology with an automated
system to detect wheat quality in single wheat kernels. It uses an
ARS-patented single kernel characterization system and a diode-array
spectrometer made by Perten Instruments. Each wheat kernel has a
unique physical composition, as shown by light being absorbed
differently at various wavelengths. An integrated fiber optic system
allows rapid analysis of two kernels per second.
ARS originally designed the system to separate hard and soft wheat
classes. In addition to hardness and disease damage, the new
instrument measures moisture, protein, color class, and hidden insects
in wheat kernels.
Scientific contact: Floyd E. Dowell, ARS
U.S. Grain Marketing Research
Center, Manhattan, Kan., phone (785) 776-2726 or 2753, fax