Astree 2 e tongue system

The corresponding detection parameters for the electronic tongue were based on the method of Han et al. [30 (link)], with minor modifications. The ASTREE II e-tongue system (Alpha M.O.S., Toulouse, France) with seven liquid cross-selective sensors (ZZ, AB, GA, BB, CA, DA, and JE) and one reference electrode (Ag/AgCl) was used to test samples. As the recognition of taste relies on the interaction between the molecules and the molecular membrane of the sensor, there is a cross-talk in the perception of taste, which further leads to the fact that the recognition of taste by the electronic tongue cannot be achieved by one sensor alone. In the initialization phase, sensors were calibrated and checked before the sample test. Subsequently, baseline stability was reached after the sensor was rinsed in cleaning water for 120 s. The samples were equilibrated for 30 s before measurement, and the acquisition time was fixed at 120 s. Each sample was measured 10 times, and the data were taken from the 8th to the 10th time. Sensors were rinsed with distilled water between each measurement. The identification and quantification of astringency were based on partial least square (PLS).

The Astree II e-Tongue system, developed by Alpha M.O.S. (Toulouse, France), was used for taste evaluation of the test example solutions. Astree II is a fully automated taste analyzer equipped with seven sensors, ZZ, AB, GA, BB, CA, DA, and JE, based on the ChemFET technology (Chemical Modified Field Effect Transistor) for liquid samples analysis (Alpha M.O.S., 2004). In the presence of dissolved compounds, a potentiometric difference is measured between each of the seven sensors and the Ag/AgCl reference electrode. Each sensor has a specific organic membrane, which interacts with ionic, neutral, and chemical compounds present in the sample solution in a specific manner. Any interaction at the membrane interface is detected by the sensor and converted into an electronic signal. The raw data is expressed as voltage versus time. For these experiments, only the last 20 s of the 120 s data was used in the analysis. Samples were replicated five times and the average value of the last four measurements is used in the data analysis. The sensors were rinsed in water following each analysis to prevent cross-contamination between samples.