One thing that can definitely ruin a wine is an unpleasant aroma. With a little help from gold nanoparticles, however, the foul-smelling wine could soon be saved.
Wine aromas come from so-called volatile sulfur compounds (VSCs). Some of them create the desired smell, but others smell more like rotten eggs, rubber, and other things you don’t want to drink. While copper sulfate is often added to wine to neutralize these problematic VSCs, it can negatively affect the flavor of the wine.
Seeking a more efficient alternative, scientists at Australia’s Flinders University devised a process that first applies a thin coating of plasma polymer to the surface of a neutral substrate. Gold nanoparticles were then fixed to this coating—gold was used because it is known to bind certain sulfur molecules.
In laboratory tests, surface-treated microscope slides were placed in 40-mL samples of white and red wine, which naturally contained high levels of unwanted VSC.
When the slides were removed after 24 hours, their nanoparticles were found to have neutralized up to 45% of the free hydrogen sulfide in the wine, as well as other unwanted VSCs such as methyl mercaptan. Importantly, these particles outperformed the copper sulfate used to match the samples.
Although more research is needed, it is hoped that one day the treatment could be applied to surfaces used in the brewing industry, such as filtration equipment, decanters and packaging materials.
A paper on the research led by Dr. Agnieszka Mierczynska-Vasilev and Prof. Krasimir Vasilev was recently published in the journal npj food science.
source: Flinders University