Cava is a quality sparkling wine produced in Spain. As a product with a designation of origin, Cava wine has to meet certain quality requirements throughout its production process; therefore, the analysis of several parameters is of great interest. In this work, a portable electronic tongue for the analysis of Cava wine is described. The system is comprised of compact and low-power-consumption electronic equipment and an array of microsensors formed by six ion-selective field effect transistors sensitive to pH, Na⁺, K⁺, Ca²⁺, Cl⁻, and CO₃²⁻, one conductivity sensor, one redox potential sensor, and two amperometric gold microelectrodes. This system, combined with chemometric tools, has been applied to the analysis of 78 Cava wine samples. Results demonstrate that the electronic tongue is able to classify the samples according to the aging time, with a percentage of correct prediction between 80% and 96%, by using linear discriminant analysis, as well as to quantify the total acidity, pH, volumetric alcoholic degree, potassium, conductivity, glycerol, and methanol parameters, with mean relative errors between 2.3% and 6.0%, by using partial least squares regressions.

In recent years, the development of information and communication technologies has notably improved the water management processes, but the technologies for water quality control still leave much scope for improvement. Specially, in situ and inline water monitoring has an increasing interest in order to take decisions at real time. The main drawbacks of the current portable meters are their high cost and their high power consumption. In this paper, it is proposed a portable compact meter for measuring simultaneously oxidation-reduction potential, conductivity, temperature, and amperometric parameters like chlorine. This system includes microsensors fabricated with microelectronic technologies, and a commercial temperature sensor, all them allowing a very low power consumption. Validation of the system has been carried out using standard solutions and comparing the results with commercial sensors. The response characteristics of sensors, in terms of sensitivity and repeatability, showed good agreement with those obtained with standard equipment using the same microelectrodes.

A previously reported methodology is applied to monitor the concentration of bacterial suspensions from an incubator using impedance spectroscopy and platinum electrodes. The interface capacitance, commonly fitted as a constant phase element, CPE_i , was found sensitive to the suspended bacteria concentration after short exposure times in a wide range of concentrations (from 10² to 10⁷ colony forming units per mL, CFU mL⁻¹) with a limit of detection of 10 CFU mL⁻¹. The effect of the substances released during bacterial growth (enzymes, toxins, exopolysaccharide, etc.) in the CPE_i magnitude was found to be negligible and samples only containing cells washed with saline solutions showed results comparable to those obtained using aliquots directly extracted from the bacterial incubator. This impedimetric approach showed correlation with classical microbiological methods for measuring bacterial concentration such as plating onto agar, optical density and fluorescence microscopy. The impedimetric approach was simplified to a single frequency analysis by selecting the optimal frequency for the measurement.

We demonstrate a portable multisensor fusion system for the automated analysis of multiple beverages. The system makes use of compact and low-power-consumption electronic equipment to simultaneously read out an array of microsensors formed by six ion-selective field-effect transistors (ISFETs), one conductivity sensor, one redox potential sensor, and two ampero-metric microelectrodes. A custom Python application running on a laptop computer receives real-time multivariate data via USB, and provides chemometric models to classify different varieties and to quantify relevant parameters of mineral water and wine. The software also includes a graphical user interface (GUI) to visualize readouts and analytical estimates.