An ‘electronic tongue’ has outperformed human senses in a test on how soon signs of faults or spoilage can be detected in white wine, said researchers in a new study.
An experiment at Washington State University (WSU) found the e-tongue picked up signs of certain microorganisms within a week of contamination – four weeks before a human sensory panel reported changes to some wines’ aromas.
The findings, published in the Journal of Food Science, are part of ongoing research and add to evidence that e-tongue technology could help with the early detection of wine faults.
Sensory probes on the so-called electronic tongue are immersed in liquid and can then identify the presence of certain compounds.
In their latest experiment, researchers deliberately added microbes associated with spoilage and unpleasant aromas to Riesling wines, leaving some bottles alone so as to have ‘control’ samples.
Wines were assessed at seven-day intervals over a 42-day storage period, pitting the e-tongue against a volunteer sensory panel.
Panellists underwent training in advance on how to spot different wine aromas considered desirable and undesirable, from notes of apple, honey and baking spices to those described as mousy, vegetal and like nail polish remover.
There was an understanding that some aromas associated with spoilage can, at low levels, add to a wine’s complexity, the study’s authors said.
Wines were served at ambient temperatures – around 22°C – and the panel used a ‘rate-all-that-apply’ method, they added.
‘If you ran a sample using the electronic tongue, we could learn after one week if there’s contamination or a wine fault problem, versus waiting up to four weeks running just sensory testing,’ said Carolyn Ross, WSU food science professor and one of the study’s authors.
Researchers added that the e-tongue was also able to ‘taste’ signs of faults before microbes could be grown from the wine in a petri-dish.
Ross and colleagues previously conducted a similar study with red wines, which also suggested the e-tongue could assist with early detection of faults.
It’s thought the technology could have several applications, and it has been programmed to ‘fingerprint’ certain wines, too, according to WSU.
But, the team said the e-tongue is best used to complement human analysis, rather than replace it.
The latest study was supported by the Washington Wine and Grape Research fund and the US Department of Agriculture.
