Citrus flavors are globally popular in food industry, yet research on the perceptual preferences of various citrus flavors is limited. Based on the subjective sensory evaluation, this study introduces a novel sensory analysis approach, using electroencephalography (EEG), to objectively measure the sensory and cognitive responses to nine citrus flavors, including d -limonene, concentrated (H-) and original essential oils of sweet orange (SEO), bergamot EO (BEO), lemon EO (LEO), and grapefruit EO (GEO). Results revealed that δ (0.5–4 Hz) and α (8–13 Hz) waves activity predominated in brain responses to citrus flavor, with greater activity observed in frontal and central regions compared to other areas. Sniffing citrus EOs triggered more complex and dynamic electrical activity than d -limonene, indicated by higher power density across all frequency bands (0.1-30 Hz). Interestingly, while the original citrus EOs were associated with higher self-reported acceptability, the concentrated forms elicited greater brain responses. Specifically, H-SEO and L-LEO eliciting significantly greater δ and α wave activity in the prefrontal region than their original forms ( P < 0.05). A preliminary correlation was observed between brain laterality in α waves power and acceptability scores of citrus flavor, with δ waves power in the prefrontal region further demonstrating an effective reflection of self-reported acceptability scores for SEO and LEO stimuli. This is the first EEG-based study to compare brain responses to different citrus flavors, providing important implications for the food industry in optimizing product formulations and enhancing consumer experiences.
Three types of tastants are known as perceptually associated with umami taste: monosodium glutamate (MSG), disodium succinate (WSA), and disodium inosine monophosphate (IMP). While these tastants were confirmed to be perceptually similar in a sensory study, they could be discriminated (p < 0.05) by electroencephalogram (EEG) analysis on a time scale of 5–6 s. In comparison of the EEG responses of the participants, the brain could partly distinguish (p < 0.05) between different sensory intensities of MSG, WSA, or IMP. The EEG data indicated that the brain is partially sensitive to perceiving different sensory intensities (L, low; M, medium; and H, high) of the same umami stimuli; i.e., for MSG in μV2/Hz, L, 2.473 ± 0.181; M, 3.274 ± 0.181; and H, 3.202 ± 0.181. However, brain responses of perceptually equi-umami intensities could partially be discriminated, suggesting that the brain could partially discriminate (p < 0.05) MSG, WSA, and IMP, despite similar sensory intensities. Moreover, umami tastants were also found to significantly enhance (p < 0.05) the α wave activity, with the most responsive being at 10 Hz, particularly in the frontal and parietal and occipital regions of the brain (p < 0.001). This study shows the potential of EEG to investigate brain activity triggered by umami stimuli.
危险品化学品经营许可证（带存储）