Integration of intelligent sensory techniques and flavoromics to elucidate the emotion-regulating mechanisms of citrus essential oils aroma

Abstract Mood foods affect emotion and cognition largely through flavor and other sensory properties, with citrus essential oils (EOs) representing key functional ingredients. Nevertheless, the mechanisms underlying their emotional effects have not been fully elucidated. This study introduces an integrative approach combining subjective evaluation using the emotion and odor scale and intelligent sensory detection technologies, including electrocardiogram, electrodermal activity, and electroencephalography (EEG), to systematically evaluate the emotional effects of citrus aromas. Multimodal analysis demonstrated that citrus EOs significantly decreased the low frequency to high frequency power (LF/HF) ratio, indicating enhanced parasympathetic activity linked to relaxation and mood improvement. EEG findings revealed increased power in the α (8–13 Hz) and δ (0.5–4 Hz) bands. Notably, navel orange, blood orange, and grapefruit EOs elicited pronounced α-band activation in the frontal, right parietal, and occipital regions. These EOs also enhanced hemispheric asymmetry in the parietal and occipital lobes, which are correlated with positive emotional regulation. Through integrated analysis of multimodal data and flavoromics (chromatography-olfactometry-mass spectrometry, odor activity value) data, D-limonene, linalool, α-terpineol, and geranial were identified as key bioactive volatiles associated with improved emotional outcomes. By linking aroma profiling with physiological and neural markers, this study shows how citrus volatiles influence mood, highlighting their potential application in functional foods and nutraceutical applications.