ABC RuralScientists discover sulphur can be good for grapes
By Richard Hudson
Tuesday, 30 August 2011
For hundreds of years sulphur has been used as a preservative to control pathogens such as fungi and bacteria.
But the latest research shows sulphur also activates or primes the defence system in grape berries.
Some people suffer allergic reactions to sulphur; that's one of the reasons why the World Health Organisation banned its use of sulphur on most fresh foods.
But the table grape industry is still allowed to use sulphur because it has struggled to find a suitable cost effective alternative.
Dr Michael Considine, a scientist at the University of Western Australia's plant biology department, says their research provides new hope of finding alternatives to sulphur preservatives.
"The magnitude of the changes that sulphur dioxide brought about in the (grape) berry was really astounding; we had no expectation that so much change was going to take place and that we might be able to find a safer alternative."
This world first research could change the way table grapes, wine and dried fruits are preserved.
Dr Considine says they are looking at UV-B and ozone fumigation as possible replacement treatments that could be available in 5-10 years.
"It may be that the ultimate outcome is that we encourage industries to find more clever way to get the residue levels down so that there aren't the potential problems for consumers, but I'm confident that there are alternatives out there."
This research could have ramifications for foods with sulphur preservatives ( E 220 to E 229 ) - products like dried fruits, jams and wines tend to use them.The ARC Centre of Excellence in Plant Energy Biology, WA's Department of Agriculture and Food and also the APC Table Grape Committee were also involved in the research.