Magnetic tongue to produce tastier tinned tomatoes

Factories could use a tongue-like detector to test flavour during production (Image: KeystoneUSA-ZUMA/Rex Features)
 
Talk about a metal mouth. A "magnetic tongue" can predict the taste of tinned tomatoes.

The sensor could help food manufacturers tweak their production methods to maximise flavour.

Experienced taste tasters rate flavours, texture and consistency on a numerical scale. Anders Malmendal, at the University of Copenhagen, and his colleagues wanted to replicate this human-like flavour detection with an artificial sensor.


They analysed the chemical composition of 18 different types of tinned tomatoes by examining hydrogen atoms with nuclear magnetic resonance spectroscopy. The proton in the nucleus of a hydrogen atom acts like a tiny magnet.

A pulse of energy flips the proton's magnetic field, and the proton releases energy as it relaxes back to its original orientation.

A hydrogen atom's location in a complex molecule like a sugar influences how quickly it relaxes, giving each hydrogen atom a unique signal based on its relaxation speed.

Using these signals, the scientists identified several common sugars and protein building blocks called amino acids in each tomato sample.

Statistical analysis correlated collections of these compounds with flavours like saltiness, sweetness, and bitterness, as ranked by trained tasters. The "magnetic tongue" tastes tomato liquid practically straight from the can.

Manufacturers could sample tomatoes during production with this sensor and quickly adjust their methods to create better tasting products, Malmendal says.

Other artificial taste and smell sensors recognize patterns of compounds connected with certain flavors as well. Electronic tongues sample wine and electronic noses sniff out insects, cancer and human skin .

Journal reference: Journal of Agricultural and Food Chemistry, DOI: 10.1021/jf203803q