The "electronic nose", which detects odours, has a companion among emerging futuristic "e-sensing" devices intended to replace abilities that once were strictly human-and-animal-only. It is a "magnetic tongue" — a method used to "taste" food and identify ingredients that people describe as sweet, bitter, sour, etc.
A report on use of the method to taste canned tomatoes appears in ACS' Journal of Agricultural and Food Chemistry.
Antonio Randazzo, Anders Malmendal, Ettore Novellino and colleagues explain that sensing the odour and flavour of food is a very complex process. It depends not only on the combination of ingredients in the food, but also on the taster's emotional state. Trained taste testers eliminate some of the variation, but food processors need more objective ways to measure the sensory descriptor of their products. That's where electronic sensing technologies, like E-noses, come into play. However, current instruments can only analyse certain food components and require very specific sample preparation. To overcome these shortcomings, Randazzo and Malmendal's team turned to nuclear magnetic resonance spectroscopy (NMR) to test its abilities as "a magnetic tongue".
The researchers analysed 18 canned tomato products from various markets with NMR and found that the instrument could estimate most of the tastes assessed by the human taste testers. But the NMR instrument went even farther. By determining the chemical composition, it showed which compound is related to which sensory descriptor. The researchers say that the "magnetic tongue" has good potential as a rapid, sensitive and relatively inexpensive approach for food processing companies to use.