Scientists working at the Universitat Autonoma de Barcelona (UAB) have created an electronic tongue, which is capable of recognizing the various types of cava wines with the help of advanced mathematical procedures and sensor systems. Classifications identical to what a sommelier does are produced automatically by the sensing device.
The cava wines differ due to the quantities of sugar which are added to the expedition liqueur after the process of secondary fermentation, which leads to the production of Carbonic gas. Hence it is important to know the correct amount of sugar that has been added. The cava wines could be classified on this basis as Sweet where >50g/L of sugar has been added, Medium-Dry (33-50 g/L), Brut (<12g/L), Dry (17-35 g/L), Extra Dry (12-17 g/L), Brut Nature (<3 g/L) and Extra Brut (<6 g/L).
Researchers from the UAB headed by Manel del Valle, recognized and identified the various cava samples with the help of voltammetric measurements. They used a number of advanced mathematical procedures such as discrete wavelet transform (DWT), principal component analysis (PCA) and artificial neural network (ANN) along with other combination of chemical measurement systems for copying the human taste system to design the electronic tongue. They were able to quantify the amount of sugar added in the cava by utilizing the second order standard addition method (SOSAM).
So far, the electronic tongue can recognize only three kinds of cava wines i.e. Medium-Dry, Brut Nature and Brut. However, in the future all the different types would be identified by proper training. The UAB Group of Sensors and Biosensors researchers have spent many years on developing electronic tongues and at present they were trying to perfect the device by the inclusion of biosensors.
The electronic tongues contain a sensor matrix which obtains chemical data from samples very similar to those received by the human senses. The perception of taste is then added by using computerized systems which interpret the information obtained from the sensor matrix. A learning and training process is also incorporated to make the electronic tongue recognize the properties of the wines.
Source: http://www.uab.es/