Magnetic nanoparticles could salvage yucky wine
If wines such as cabernet sauvignon contain high amounts of chemical compounds known as alkylmethoxypyrazines (MPs), their fruity/floral bouquet can be overwhelmed, resulting in an off-putting flavor and aroma. Now, scientists have used magnetic nanoparticles to remove MPs from wine like never before.
Excessive MP content can occur when wine grapes are harvested early, or grown in cold climates. Wine makers have tried neutralizing them via additives including deodorized oak chips and activated charcoal, although these approaches reportedly haven't met with much success.
There are also films made from polylactic acid (PLA), which will draw a limited amount of MPs from wine when laid on top of it.
Led by associate professor David Jeffery, a team at Australia's University of Adelaide recently developed a more effective alternative – magnetic nanoparticles containing an MP-absorbing polymer.
In lab tests, these were mixed into a cabernet sauvignon post-fermentation, that was spiked with a particular type of MP. When the particles were subsequently removed from the wine using a magnet, gas chromatography and mass spectrometry revealed that they took up to 74 percent of the MP concentration with them. The wine's aroma intensity wasn't affected, according to a group of taste testers.
By contrast, when a commercially-available PLA film was used on the same wine, it only removed 18 percent of the MP concentration.
A paper on the research was published this week in the Journal of Agricultural and Food Chemistry.