Investigating the Mechanism Underlying Umami Substance Detection in Taste Sensors by Using 1H-NMR Analysis

Previous studies have reported the development of a taste sensor using a surface modification approach to evaluate umami taste, specifically substances like monosodium L-glutamate (MSG) and monosodium L-aspartate. The sensor was modified with 2,6-dihydroxyterephthalic acid (2,6-DHTA). However, the mechanism underlying umami substance detection in the 2,6-DHTA- treated sensor remains unidentified, as does whether the specific detection is due to an intermolecular interaction between the modifier and the analyte. In this study, 1H-NMR measurements were conducted for a variety of modifiers and analytes in terms of structures, along with taste sensor measurements. By comparing the 1H-NMR spectra and the results of the taste sensor, we suggested that both modifiers and analytes need to meet certain molecular structure conditions to produce intermolecular interactions. The modifier needs to possess intramolecular H-bonds and have carboxyl groups in the para position of the benzene ring, i.e., two carboxyl groups. In conclusion, we validated that the response mechanism of the taste sensor for umami substance measurement proposed in previous studies is reasonable and predicted the binding form of 2,6-DHTA and MSG.