7 June 2002

A nose for spoilage…

Work to produce an electronic nose to give an early warning of spoilage in grain stores is progressing apace. Its developers hope it could soon be used at mill intake to reject damaged loads.

"A prototype sensor device to detect off-odour in grain has been developed with the assistance of HGCA funding," says CCFRAs Helen Brown.

In conjunction with industry collaborators, CCFRA and the University of the West of England, a prototype sensor suitable for use at intake has done well in early trials.

"Off-odours from spoiled grain cost the industry significant amounts of money each year and can be difficult to detect due to both the presence of other odours and variability in human sensory detection, says Dr Brown.

"Sometimes you can take in grain which appears to be alright, yet during production spoilage odour is released creating a problem after value has already been added."

During the testing, grain is first temperature equilibrated to 80C and then air passed over the sensors for 15 seconds. Sensors react to volatile compounds in the air stream that and an electrical signal is emitted.

A prototype device suitable for laboratory use was tested in a commercial wheat intake laboratory.

Over a two week period samples arriving at wheat intake were analysed using the sensor alongside the usual human assessment, which is smelling the grain. The sensor correlated well with results from the human assessments.

"The prototype performance was promising in a grain intake situation, says Dr Brown.

"Our ultimate objective is to develop a device suitable for use in a commercial situation that will replace human sniffing and remove associated subjectivity in the majority of cases," says Dr Brown.