Partial Replacement of Coffee with Roasted Corn: Sensory Responses of Regular and Specialty Coffee Consumers

Introduction Coffee is among the most widely consumed beverages worldwide. Supply uncertainty and price shocks have renewed interest in coffee substitutes, coffee extenders, and beverages designed to reproduce selected sensory characteristics of coffee using other botanical materials. A critical distinction must nevertheless be made between transparently formulated coffee alternatives or blends and the undeclared addition of lower-cost materials to roasted coffee. In the latter case, substitution constitutes adulteration and compromises product authenticity and consumer trust. Objective This study investigated consumption habits and sensory responses to beverages in which roasted corn replaced 0%, 1%, 10%, 20%, or 30% of coffee. Methodology Of 115 participants, group comparisons involved 69 regular coffee consumers (RCC) and 40 specialty coffee consumers (SCC). Participants reported their habits, evaluated six attributes using a just-about-right (JAR) scale (color, coffee aroma, sweetness, bitterness, acidity, and body), free-listed sensory characteristics, and rated aftertaste and overall liking. Formulations were compared within groups by analysis of variance and Tukey’s test. Result Daily consumption was similar, but RCC purchased coffee mainly from supermarkets, whereas SCC used diversified channels. For RCC, formulations containing up to 10% corn did not differ from the control in color, aroma, or body; 10% corn received higher overall liking than 20% corn but did not differ from the control. For SCC, 20% corn received higher aftertaste and overall liking than the control. Conclusions Increasing corn reduced bitterness toward the JAR midpoint in both groups, whereas higher concentrations weakened coffee aroma and elicited cereal flavor, watery character, and lack of characteristic coffee flavor. Sweetness did not differ among formulations. Roasted corn generated concentration- and consumer-dependent sensory trade-offs. Formulations containing 10% and 20% corn warrant further validation for RCC and SCC, respectively, as transparently labeled coffee-based beverages.