Human Perception-Calibrated Electronic Tongue for Quantitative Bitterness Prediction and Characterization of Sucrose-Induced Sensor Response Modulation

Electronic tongue signals can provide objective measures of taste-related responses, but their quantitative correspondence with human perceptual intensity remains insufficiently characterized. This study developed a psychophysically calibrated electronic tongue framework for quantitative bitterness evaluation and sucrose-induced sensor response modulation. Concentration-dependent responses to quinine hydrochloride, berberine hydrochloride, and iso-α-acid followed logarithmic relationships, with coefficients of determination of 0.983, 0.910, and 0.984, respectively. By integrating these instrumental relationships with psychophysically derived sensory bitterness references, compound-specific conversion models were established to translate electronic tongue signals into psychophysically derived bitterness reference values. Validation using additional electronic tongue measurements yielded mean absolute percentage errors of 6.02%, 10.76%, and 7.14%, respectively. Electronic tongue responses to the three bitter compounds exhibited varying trends under 0%, 2%, and 8% sucrose backgrounds, suggesting compound-dependent effects of sucrose on sensor responses. The proposed framework provides a quantitative link between electronic tongue responses and psychophysically derived bitterness reference values, with potential applications in sucrose-containing systems.