- While previous research has suggested that bitterness is the key determinant of vegetable disliking, it is unknown what role odor plays in vegetable hedonics. We therefore investigated the impact of odor as well as taste on liking and disliking of four vegetables (steamed asparagus and Brussels sprouts; fresh celery and snap peas). To minimize the visual and textural cues, the vegetables were finely chopped. Subjects (N=132) tasted the samples with the nose open and also with the nose closed and rated the degree of liking/disliking as well as perceived intensities of sweetness, bitterness, saltiness, and vegetable flavor on the LHS and gLMS, respectively. Subjects were classified as 'likers' or 'dislikers' of each vegetable based on the valence of their hedonic ratings under the nose open condition (i.e., when retronasal odors could be perceived). The degree to which 'likers' liked and 'dislikers' disliked the specific vegetables was significantly less (p<0.05) in the nose closed condition, indicating that odor was a significant driver of vegetable hedonics. Importantly, perceived vegetable odor intensity did not differ significantly between 'likers' and 'dislikers' for most of the vegetables, suggesting that the quality of vegetable odors, but not their perceived intensity, generally drove hedonic ratings. In contrast, taste intensity ratings measured in the nose closed condition sometimes differed significantly (p<0.05) between 'likers' and 'dislikers', but not in a consistent manner across vegetables. More importantly, perceived bitterness ratings measured in the nose closed condition did not differ significantly between 'likers' and 'dislikers' for any vegetable. However, specific vegetable 'dislikers' rated the perceived bitterness higher than 'likers' in the presence of retronasal odor, especially for those "bitter" vegetables, which implies that bitterness is often confused with the odor of vegetable in the normal tasting condition. In order to further investigate the role that specific odors play on liking and disliking of vegetables, a follow-up experiment was conducted. Returning subjects sampled and rated the degree of liking/disliking of the odor of the 4 test vegetables, which were presented retronasally and orthonasally in the absence of other sensory cues. Degree of retronasal odor liking was significantly higher (p<0.05) for the specific vegetable 'likers' than by their 'disliker' counterparts for the 4 vegetables. Degree of orthonasal odor liking was also significantly higher (p<0.05) for asparagus and snap pea 'likers' than their 'dislikers', but no such difference was found for the other two vegetables tested. Overall, these results suggest that odor, especially retronasal odor, is a significant driver of vegetable liking and disliking, while tastes of vegetables play a lesser role.