Takehiko Hiura, a PhD student at Heriot-Watt University, analysed 14 whiskies from Scotland and Ireland and found that aldehydes and acetals, compounds that are common in whiskies, can increase tropical aroma properties.
These compounds are formed during fermentation and barrel maturing.
The study found that one whisky contained particularly high levels of three key compounds: isobutyraldehyde, isovaleraldehyde and isovaleraldehyde diethyl acetal.
When the team spiked a whisky presenting as low for mango aroma with these chemicals, the fruity aroma increased substantially. This could potentially give producers the ability to increase this aroma in their whiskies.
Professor from Heriot-Watt’s International Centre for Brewing and Distilling (ICBD) Annie Hill said: “Fruity notes like banana, apple and pear have long been linked to esters, which are produced during fermentation. But we didn’t know where the mango flavour was coming from - and now we do.”
Dr Calum Holmes, also from the ICBD, said: “The compounds that we found contribute to tropical notes, the aldehydes and acetals, aren’t new to whisky, they’re well understood.
“For whisky producers, that’s good news: it means they can hopefully dial up or tone down tropical aromas by manipulating existing process steps.”
Heriot-Watt has been at the forefront of research in brewing and distilling.
In 2019, its scientists identified the gene in barley which is responsible for drought resistance, which could help the Scotch whisky and wider cereals industry respond to climate change.
Previously, the University also joined forces with The University of Edinburgh to use Nuclear Magnetic resonance spectroscopy that can take the chemical fingerprint of different types of gin.
Heriot-Watt is raising £35 million for its new Centre for Sustainable Brewing and Distilling.
Heriot-Watt researchers were working with Japanese drinks giant Kirin when they made the discovery.
