Olfaction modulates taste attributes in different types of chocolate

Bitterness is considered an unpleasant taste, while also dominating the flavor of highly liked foods like chocolate. Adding dark chocolate aroma to a cocoa beverage enhances bitterness via cross-modal interactions. Foods naturally contain volatiles that can affect taste, so the influence of endogenous aromas on chocolate bitterness was investigated here. Specifically, we explored effects of olfaction, roasting and cocoa mass content in two experiments with regular chocolate consumers rating overall liking and intensities of bitterness, sweetness, sourness, astringency, cocoa flavor, and grittiness. Nine differently roasted 100 % chocolates (Experiment 1) and three commercial chocolates varying in cocoa content (0–100 %; Experiment 2) were assessed in two session crossover designs with and without olfactory input. In Experiment 1, we found significant interactions between roasting conditions and olfactory input for all attributes, but not overall liking. Greater olfactory enhancement of bitter and sour taste and astringency were observed for chocolates roasted at lower temperatures. We also saw a significant interaction between cocoa content and olfactory input for sour and bitter tastes, with greater odor enhancement of these tastes at a higher cocoa content. In Experiment 2, the 100 % commercial chocolate showed a smaller olfactory effect on bitterness than in Experiment 1, implying that aroma quality also affects olfactory enhancement of bitterness and sourness in chocolate. Collectively, the effect of olfaction on taste and mouthfeel perception in chocolate is complex and depends on both cocoa content in the chocolate and how the cocoa has been roasted.