Nanotechnology surface engineering for better wines

(Nanowerk News) The new ‘smart surface’ has proven successful in removing unwanted sulfurous aromas from wine, opening up new opportunities for winemakers.

Developed by scientists from the Australian Wine Research Institute (AWRI) and Flinders University, the technology is based on applying a thin layer of plasma polymer to a surface and then immobilizing nanoparticles on the surface, which then bind strongly to the sulfur compounds in the wine.

A new surface trial, recently published in the journal npj Food Science (“Surface nano-engineering technology for removing sulfur compounds associated with negative attributes in wine”), removes up to 45% of free hydrogen sulfide from wine and the treatment is also effective for removing more complex sulfur compounds, such as methanethiol.

“The main benefit of this new approach is that it is easy to apply and retrieve. There is basically a one-step process where smart surface is added directly to the wine and then removed after a certain amount of time,” said AWRI Principal Research Scientist, Dr Agnieszka Mierczynska-Vasilev.

As the developed nano-engineered surfaces are independent of the substrate material, there is also potential for application to a wide range of relevant wine equipment such as filtration devices, aerators, decanters, packaging materials or caps.

Co-author of the study, Professor Matthew Flinders Krasimir Vasimir, said the Biomedical Nano-Engineering Laboratory at Flinders University was instrumental in delivering “technological breakthroughs to improve winemaking” in collaboration with AWRI experts.

Professor Vasilev and AWRI colleagues have also published in Food Chemistry (“A new solution for tartrate instability in white wine”) on new solutions for tartrate instability in white wine.

Volatile sulfur compounds (VSCs) are a group of compounds that contribute significantly to the aroma of wine. While some contribute positive varietal characters, others are associated with negative ‘reductive’ odors such as ‘rotten egg’, ‘rubber’ and ‘canned corn’. The management of these off-aromas is a significant cost to the wine sector.

The new smart surface has been shown to outperform traditional wine processing with the addition of commonly used copper sulfate to avoid unwanted volatile sulfur compounds. In addition, unlike copper sulfate, it does not have a negative effect on taste.

The next step in developing smart surfaces for application in the wine sector is currently being explored.