Wine tester

Wine producers will be better equipped to deliver a high-quality harvest, thanks to a new microsensor developed by RMIT University in Australia.

RMIT, funded by the Cooperative Research Centre for Viticulture (CRCV), collaborated with the Victorian Department of Primary Industries (DPI) and the Cooperative Research Centre for Microtechnology, to develop the microsensor, which allows grape growers to better test for chemical residue levels in their products.

The device provides a rapid, inexpensive method of measuring chemical residues on-site and will aid growers in deciding on safe harvest dates and whether their product complies with market requirements. Such decisions often need to be made quickly, and existing testing methods can be too time-consuming and expensive.

CRCV CEO Jim Hardie said that pesticide residues were a key quality indicator for the Australian wine industry.

'Compliance with Maximum Residue Limits (MRLs) is essential in both domestic and export markets and, consequently, technologies such as this microsensor are of considerable interest to the industry,' he said.

MRLs are defined as the maximum concentration of pesticide residue (expressed as milligrams of residue per kilogram of food/animal feeding stuff) likely to occur in or on food and feeding stuffs after the use of pesticides according to Good Agricultural Practice, i.e. when the pesticide has been applied in line with the product label recommendations and in keeping with local environmental and other conditions.

Project coordinator Michelle Warren  from the DPI explained that the microsensor combined the use of two technologies.

'A chemical recognition system known as Molecular Imprinted Polymers was chosen as the most appropriate for detecting pesticides in grape tissue. This was then coupled with an Acoustic Wave Sensing device developed by RMIT, which provides the high level of sensitivity required for use in the wine industry,' she said.

'The combined technologies provide a simple means of reliably measuring any biocide residues on the farm,' she added.

Prof David Mainwaring, Dean of Research and Innovation for Science, Engineering and Technology at RMIT, said that the microsensor could detect the pesticide iprodione in white wine and grape juice. Iprodione was often used late in the growing season and therefore presented a potential residue risk.

'Now that we know it can detect iprodione, we need to compare the device with traditional methods of pesticide residue analysis,' said Prof Mainwaring. 'If the microsensor proves to be reliable, it provides a path towards commercial applications.'

Prof Mainwaring added that the technology also had potential applications in a range of other food industries and in fields such as water quality monitoring.