On-farm storage - Electronic 'nose' sniffs out trouble

Dr Colin Waterford

Dr Colin Waterford, head of the CSIRO’s Stored Grain Research Laboratory, is shown with the latest piece of sophisticated gadgetry for protecting the quality of stored grain.

This is the grains industry’s version of the sniffer dog – an ‘electronic nose’ that can potentially detect the early growth of fungi or mould.

More formally referred to as ‘electronic aroma sensing technology’, it uses gas chromatography to detect quality changes in grains. Mould and fungal contamination, which can reduce the nutritional value of grain and potentially result in the production of dangerous mycotoxins, causes offodours and these are detected and identified by the electronic nose.

Dr Waterford says the advantage of electronic nose technology is its capacity to carry out rapid assessment of grain quality at an early stage to help maximise and maintain grain quality during storage.

The electronic nose is relatively new and is designed to simulate the human nose. Volatile organic compounds are picked up in a carrier gas stream and passed over detectors. These comprise an array of chemical sensors that are selective for particular types of volatile components.

When the sensors absorb the volatile compounds carried in the gas, the electrical resistance changes, enabling a mathematical fingerprint of the components to be created. Aroma sensing is rapid and simple and is capable of remote or on-line analysis.

The equipment can discriminate between samples of wheat or canola with different quality characteristics and storage histories. It is also possible to differentiate between hard and soft wheats, with distinct peaks formed on the chromatograph for each grain sample. This shows the system has the potential to identify and quantify specific volatiles characteristic of different grain types.

Electronic nose technology shows considerable promise in helping the grains industry in the areas of early detection of insect growth, quality changes, varietal differences in grain, characteristic odours in well and poorly stored grain, and detection of chemical residues.

For more information:
Colin Waterford, 02 6246 4204, colin.waterford@csiro.au