Crossmodal correspondence is of scientific and commercial interest in regard to the packaging of food and beverages. Research has shown that colors and shapes can be associated with certain aromas, but these interactions have been less extensively studied with authentic visual stimuli (i.e., packaging), nor with complex odors in a food matrix. This study sought to investigate odor-color-shape crossmodal interactions with complex odor stimuli (wine odors) and wine labels. The present research uses projective mapping with 3D shapes and colors, along with a wine label matching study, to test whether chardonnay odors of different character (buttery, citrus, floral, smoky, and vegetable) are associated with certain colors and shapes. In the projective mapping experiment, most chardonnay odors were grouped similarly, however, the vegetable-forward wine was more associated with sharper shapes than rounded ones. In the wine label experiment, the yellow labels tended to be better matched with all odors, except the vegetable-forward wine, which was matched equally to all colors. These findings indicate that regardless of chardonnay odor character, it is mostly associated with a yellow colored label. Interestingly, results also indicated that not all correspondences aligned with the most common color association of an odor character (i.e., vegetative was not strictly associated with green, smoky was not associated with brown, etc.). Significant correlations between stimuli liking and matching scores indicate much of the correspondences are explained by hedonics. Overall, the present research demonstrates evidence for odor-color-shape correspondences in complex odors and realistic visual stimuli, however not as strongly as in controlled environments and simplistic stimuli.

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There are key unanswered questions when it comes to odor mixture discrimination. This study was designed to assess one of those questions regarding configural odor mixture discrimination in humans. We collected data to address the following two questions: 1) What factors do humans notice when attempting to discriminate between subtly different odor mixtures? 2) Are odor mixtures easier to discriminate when an odorant is added, compared to when a component is removed? Using modern flavor chemistry techniques, an odor mixture resembling a Riesling wine was constructed. This wine odor mixture was modified using a homologous series of 3 esters, varying in chain length, which are commonly found in white wines. A sequence of discrimination tasks for the addition / subtraction of modifiers to the base wine at different concentrations were employed to gauge the discriminatory ability of the participants. The concentration of a modifying odorant appears to be a key factor in discrimination. As concentration of the modifying odorant was increased, discrimination of odor mixtures was first reported because of changes in odor mixture familiarity. Humans show similar sensitivity to odor mixture discrimination regardless of addition or subtraction of modifying compounds, and this study shows that human odor mixture discrimination is driven by changes in odor quality. Additionally, we find that evidence pattern completion may not be the only mechanism favoring perceptual stability in olfactory processing, especially in the presence of chemesthetic and visual information.

There are key unanswered questions when it comes to multicomponent odor discrimination. This study was designed to assess discrimination of odorant mixtures that elicit a singular percept. We collected data to address the following two questions: (1) What odor features do humans notice when attempting to discriminate between subtly different odor mixtures? (2) Are odor mixtures easier to discriminate when an odorant is added, compared with when a component is removed? Using modern aroma chemistry techniques, an odor mixture resembling a generic white wine was constructed. This wine odor mixture was modified using a series of three esters which are commonly found in white wines that vary in chain length and branching. Participants performed a sequence of discrimination tasks for the addition/subtraction of modifiers to the base wine at different concentrations. Only one of the esters (ethyl propanoate) led to a discriminable odor mixture. As concentration of the modifying odorant was increased, discrimination of odor mixtures was first reported because of changes in odor mixture familiarity and then intensity. We found similar sensitivity to changes in odor mixtures regardless whether the modifying compound was added or subtracted, suggesting that perceptual stability of odor mixtures is equally dependent on both imputing missing information (pattern completion) and disregarding extraneous information.