The limitations of the nose

Enjoying a good wine is one of the pleasures of life and part of that enjoyment is its bouquet. Imagine, then, how important the ability to distinguish both the good and bad odours in wine is to winemakers.

Currently, the measurement of wine odours relies on well-trained human noses. However, Australian scientists are part of the worldwide search for an objective way of quantifying odours with the development of the Cybernose. Their first target is the wine industry.

In an address to the Australian Wine Industry Technical Conference (AWITC) in Adelaide, CSIRO's Dr Stephen Trowell, quality biosensors theme leader in the Food Futures Flagship, said that while other research teams are looking at using odour receptors from a wide range of sources in odour-detection devices, Australian research is concentrating on the receptors in simple organisms such as insects and nematodes.

"While the human nose is a wondrous thing, it has its limitations," Trowell says.

"Research on more reliable alternatives has involved two main approaches -- the use of mass spectrometry to look at the molecular structure of each component and an array of electronic detectors known as an 'electronic nose'.

"Both technologies have their place but the mass spectrometer is much slower and less sensitive than the human nose in some instances while the electronic nose is less discriminating.

"Now we are exploring the use of sensor proteins on the front-end of an electronic nose, a Cybernose," he said.

"Using these, we hope to build on the remarkable ability of small organisms to distinguish between odours and even pick up odours not detectable by humans. Our aim is to provide wine makers with devices they can use anywhere to detect contaminants, the level of ripeness of grapes and also either individual positive odorants or a broader odour pattern associated with a particular style of wine."