Portable electronic tongues could provide a cheaper and more flexible way for wine makers to test the maturity of their grapes.
The voltammetric electronic tongue used by researchers at the Universitat Politècnica de València in Spain consists of eight metallic electrodes housed inside a stainless steel cylinder that provide data for software that can detect the chemical composition of a solution.
In collaboration with Valencia winery Torre Oria the team measured the maturity of eight different types of grapes – Macabeo, Chardonnay, Pinot Noir, Cabernet Sauvignon, Shyrah, Merlot and Bobal – in several locations
Results published in journal Food Research International show a good correlation between the response of the electronic tongue and parameters analysed in traditional tests to determine when grapes should be harvested: the acidity of the fruit and sugar levels.
And according to Ramón Martínez Máñez, researcher at the University’s Centre for Molecular Recognition and Technological Development, the tongues have the advantage of being both cheap and portable.
"The latter is especially useful to assess the degree of ripeness as with current methods of analysis further assessment in a laboratory is usually required," he said.
According to the researchers, the ability of the device to perform analysis on the fruit at source has been highlighted by producers as a major selling point.
The researchers are currently working on new applications of electronic tongues in the sector, in particular their use to control the fermentation of grapes in vats.
"These devices allow performing a continuous monitoring of the process, which would result in greater control over the product, and ultimately an increase in competitiveness," adds researcher Inma Campos.