An artificial "tongue" which can taste subtle differences between whiskies could help tackle the trade in counterfeit alcohol trade, scientists say.
In a paper published in the Royal Society of Chemistry’s journal Nanoscale, Scottish engineers describe how they built the tiny taster, which exploits the optical properties of gold and aluminium to test the differences between the spirits.
The technology was able to taste the differences between the drinks with greater than 99% accuracy. It was also capable of picking up on the subtler distinctions between the same whisky aged in different barrels and can also tell the difference between whiskies aged for 12, 15 and 18 years.
Alasdair Clark, of the University of Glasgow's school of engineering, said: "We call this an artificial tongue because it acts similarly to a human tongue – like us, it can't identify the individual chemicals which make coffee taste different to apple juice but it can easily tell the difference between these complex chemical mixtures.
"We're not the first researchers to make an artificial tongue, but we're the first to make a single artificial tongue that uses two different types of nanoscale metal 'tastebuds', which provides more information about the 'taste' of each sample and allows a faster and more accurate response."
“While we’ve focused on whisky in this experiment, the artificial tongue could easily be used to ‘taste’ virtually any liquid, which means it could be used for a wide variety of applications. In addition to its obvious potential for use in identifying counterfeit alcohols, it could be used in food safety testing, quality control, security – really any area where a portable, reusable method of tasting would be useful.”
Researchers poured whisky over a chequerboard pattern of the two metals – which act as "tastebuds" – and researchers then measured how they absorbed light while submerged.
Statistical analysis of the very subtle differences in how the metals in the artificial tongue absorb light – what scientists call their plasmonic resonance – allowed the team to identify different types of whiskies.
The team used the tongue to sample a selection of whiskies from Glenfiddich, Glen Marnoch and Laphroaig.
The research was conducted by engineers and chemists from the universities of Glasgow and Strathclyde.
Their paper, titled 'Whisky tasting using a bimetallic nanoplasmonic tongue', is published in Nanoscale.
