65 Sensor technology for measuring grain volatiles and odors.

L. M. SEITZ.

Odor is an important factor in grain grading, and an objective and safe method for classifying odors in grain is needed. To gain information relating to this problem, we have used purge and trap (dynamic headspace) technology coupled with gas chromatography-mass spectroscopy to determine volatiles in several large sets of samples with known odors. Results from these tests have shown that specific compounds are associated with off-odors, and that certain volatiles can indicate problems with insects, molds, heating, and other adverse conditions in grains. Sensors for rapid and convenient detection of volatiles will probably be required in instrumentation to be used routinely by grain inspectors or to provide capability for Aon-line@ testing. Several types of sensors and sensor arrays have recently become available for detection of volatiles. Commercial Aelectronic nose@ instruments are available that utilize sensors arrays and pattern recognition software. Our data on compound-odor relationships and appropriate groups of samples with known odors contribute to training these instruments to recognize normal and abnormal odors. Application of Aelectronic nose@ instruments for odor classification with grain samples is in an early stage of testing.