When I was a kid growing up in Extremadura, in the southwest of Spain, I knew I wanted to be an electronic engineer. I loved to take apart lightbulbs and electronic devices. But it was not until I was 24 that I discovered where to focus my passion: odours.
I’d moved to Madrid to do a PhD at the School of Physics there and one day in 1999 my thesis director took me to a wine-tasting. I’d never been to one before and I was blown away by the complexity of wine and how much aromas could tell you about it. I’d never realised that, for example, if the wine smelled of pencils it meant a fresh oak barrel had been used for the winemaking process. At dinners, I found myself thinking how great it would be to have a device that could help to scrutinise the aroma of a bad wine.
Eventually, I joined a project at the Spanish National Research Council in Madrid. Researchers there had built one of the first “electronic noses” in Spain, in the 1990s, to detect air pollutants coming from an incineration plant. Now they wanted to build a device that could analyse the aromas of wines with a Madrid appellation of origin, in order to improve their quality. I’ve been building e-noses ever since.
They’re used to distinguish the smells of common defects in wine, including corked and oxidised wine. They can tell apart wines aged in expensive oak barrels from the inferior ones infused with chips to simulate the aroma. As they can also recognise different varieties of grapes, they can help to protect the appellations of origin of wines. An e-nose can really help cut down wine fraud and protect the consumer.
A human nose can become fatigued. If it smells an odour for long enough, it will eventually stop noticing it. And there are odours that it simply can’t detect. Tasting panels are widely used in quality control in the food and wine industries, but the number of analyses that can be done in a day is limited, since smelling certain scents for too long reduces your olfactory sensitivity. A wine or olive oil tasting panel can’t possibly assess the quality of every bottle that is produced. An electronic nose can just keep on working!
The human nose’s biggest problem, however, is how subjective it is. People perceive smells very differently. Even having a bad day can shape our perception. An e-nose doesn’t have feelings.
Some of my colleagues developed an e-nose that could distinguish expensive Iberian ham – which should come from pigs that roam freely and feed only on acorns – from inferior cured hams made with pigs reared in factories on feed. These inferior hams are very often labelled as Iberian ham and this is a way of detecting the fraud. You can do exactly the same with olive oil.
Now I work at the University of Extremadura’s Sensory Systems Research Group, where we are trying to produce cheaper models, to help overcome commercial resistance to e-noses. We recently developed two handheld portable e-noses, which we estimate could cost just a few thousand euros on the market. Their results are ready in minutes.
I believe in a not-so-far-away future that these devices will be common in everyday life. E-noses will be installed in fridges and microwaves to alert us if food has spoiled or burnt. They could really help older people, as we lose our sense of smell as we age.
Of course e-noses can’t replace the human nose. But I bet that one day we will all have our own cheap and portable electronic noses, tiny enough to carry in our pockets, to check the quality of food and drink before we buy it.