Comparative Study of Taste Substance Sensing by Liquid Membrane Oscillator and Electrochemical Systems With All-Solid-State Electrodes

In food industry, different types of sensors are used for characterizing and quantifying taste substances. Therefore, it is important to establish the principal advantages and disadvantages of these sensors for optimal application. In this paper, two possible systems are compared for sensing the four fundamental tastes: sour (citric acid), salty (sodium chloride), sweet (sucrose), and bitter (caffeine or quinine hydrochloride). One system is a bulk liquid membrane oscillator containing benzyldimethyltetradecylammonium chloride surfactant present during its transport in nitrobenzene membrane phase. The other system is based on all-solid-state electrode (ASSE) containing the same surfactant dissolved in polymer support. It was shown that the liquid membrane oscillator is significantly more sensitive to the presence of taste substances than the ASSE III system. Unfortunately, the functioning characteristics of this oscillator prevent it from steady, repetitive application in food quality control. On the other hand, ASSE III system shows remarkable stability on the long run. It was also found that a system composed of several ASSEs III, each containing different lipid compound, can distinguish successfully substances belonging to different taste classes. The obtained results suggest that such ASSEs III system can be used for food analysis.