Decoding Bitter Taste Perception in Medicine-Food Homology Substances: A Multimethod Data and Sensory Assessment Approach

Medicine and Food Homology (MFH) substances are often limited by bitter off-flavors that may limit consumer acceptance. This study employed a multimethod approach integrating electronic nose (E-nose), sensory evaluation, electronic tongue (E-tongue), gas chromatography-ion mobility spectrometry (GC-IMS), and electroencephalography (EEG) to investigate bitterness perception in five representative MFH extracts (Chenpi, Lotus leaf, Sichuan pepper, Gardenia, and American ginseng). Sensory and E-tongue analyses revealed discrepancies between perceived and chemically measured bitterness. GC-IMS identified distinct volatile fingerprints, highlighting differences in aroma composition among samples. EEG results showed that several conventionally bitter extracts were primarily associated with low-frequency scalp-EEG activity (δ–α bands), whereas Sichuan pepper showed an apparent delayed broadband increase extending into the β–γ range. Descriptive scalp EEG patterns varied across MFH stimulation conditions, including differences at frontal and temporal electrodes. Overall, this study provides an exploratory multimethod characterization of the sensory, instrumental, and scalp-EEG responses elicited by different MFH extracts.