Clean labeling efforts may mean colorants will be avoided, yet color may prove essential in capturing how consumers perceive a food product, noted Debra Zellner, Ph.D., Professor of Psychology at Montclair State University, and Affiliated Faculty Member at Monell Chemical Senses Center. Zellner provided an illuminating discussion of how the color of food (and its packaging) affects consumers’ expectations for odor and flavor in her presentation: “The Effect of Color on Odor Perception: Toward More Efficient Ingredient Use.”
The odor associated with food is perceived orthonasally (when detecting the food’s aroma) or retronasally (when food is in your mouth, i.e., “flavor”).
Food color affects the perceived intensity of orthonasal odor, with colored foods (regardless of color) rated as having more intense odors than clear foods. In contrast, colored foods were perceived retronasally as less intense than clear foods.
Food color also affects flavor identification, which in turn affects how well a consumer likes a food. “Most people are terrible at identifying flavors or odors,” commented Zellner. If the flavor and color of a food are incongruent, subjects will perceive the flavor to be something congruent with color. For example, a clear cola soda might be perceived as lemon/lime rather than cola.
How well a color matches the flavor of a food also affects how well the food is liked, with foods less well-liked when their flavor and color are incongruent—unless it is apparent what the flavor is supposed to be. As explained by Zellner, “Green beer is still okay on St. Patrick’s Day,” because you know the beverage tastes like actual beer—not mint or apple.
Zellner detailed some of the psychology underlying these results. When stimuli are paired together repeatedly over time, an association between them develops. For example, if you are a coffee drinker, a brown-colored beverage will elicit the perception of coffee. The odor perception due to the color alone is similar but weaker than that produced by the actual stimulus [i.e., coffee aroma], but color can add to and enhance the actual odor.
One recent study tested how a raspberry/lemon-flavored beverage was perceived when colored yellow, red or left clear. When colored yellow, the soda had more of lemon aroma than did the same beverage when red or clear in color. The effect was limited to the scent, however, because the color did not influence the perceived taste of the beverage
Inspired by New York Times food critic Mimi Sheraton, Zellner’s group also investigated whether packaging color provides a clue to the flavor of the food inside. Unflavored, neutral- colored hard candies were wrapped in various colored papers. When still wrapped, the color of the wrapper influenced what flavor the subjects believed the candies were. After unwrapping, however, the wrapper color did not affect the flavor subjects assigned to the candy. Most subjects predicted that unwrapped, neutral-colored candies were mint, vanilla or coconut in flavor. The perceived flavor when tasting the uncolored candy was often vanilla or butterscotch, flavors normally associated with neutral colors.
A similar study in potato chips (which looked alike, despite different flavors) found that packaging colors affected the perceived flavor of the chips, but only if the subject was already familiar with the packaging color scheme used for different flavors.
In summary, food or packaging color can influence odor or taste perception or expectation in a variety of ways. Food color increases orthonasal (sniff) but not retronasal (in the mouth) odor perception; color can intensify one odor component in a complex product with multiple odors; color does not increase flavor intensity, but color will change expectation, identification and enjoyment of a flavor; and food color matters more than the packaging color, especially when food color predicts flavor. However, when all flavors look similar, packaging colors can influence flavor expectations.
“The Effect of Color on Odor Perception: Toward More Efficient Ingredient Use,” Debra Zellner, Ph.D., Professor, Psychology, Montclair State University & Monell Chemical Senses Center