Decoding pleasure perception of citrus essential oils: Integrating GC-MS flavor chemistry with EEG and fNIRS...

Pleasure perception drives consumer preference for citrus essential oils, but traditional evaluation is lack of objective physiological validation. Herein, a multimodal framework integrating hedonic sensory evaluation, electroencephalography, and functional near-infrared spectroscopy was established to assess ten citrus essential oils. Based on pleasure ratings, the samples were categorized into high-, medium-, and low-pleasure groups. Neuroimaging revealed that high-pleasure essential oils significantly induced frontal alpha asymmetry (-0.005 to 0.038) and orbitofrontal cortex activation (-0.785 to 3.399), validating these metrics as objective reward markers. Ninety volatiles were identified through gas chromatography-mass spectrometry, and 48 key pleasure-related volatiles were screened using relative odor activity value and variable importance in projection. Correlation analysis indicated that several volatiles such as beta-caryophyllene and alpha-pinene are positive pleasure drivers, whereas beta-pinene and carvone are negative drivers (p < 0.05). This study objectively quantifies flavor-induced pleasure and provides a scientific basis for flavor design of citrus-based products.