Spent Coffee Grounds as a Viable Byproduct Alternative for Cocoa in Muffins: Physicochemical and Sensory Characterization

Coffee is one of the most widely consumed beverages worldwide, and spent coffee grounds (SCG) are the most abundant byproduct of the global coffee industry. Valorizing SCG contributes to ecological sustainability while at the same time providing economic advantages to the foodservice sector. Cocoa, although a preferred flavoring ingredient among consumers, presents drawbacks such as unreliable supply, high cost, and the presence of potentially toxic compounds. This study explores the potential of SCG as a sustainable alternative to cocoa in muffin formulations by analyzing its physicochemical properties and conducting a consumer sensory evaluation with 135 panelists. The most relevant improving advantages of SCG compared to cocoa powder are more fiber, a higher antioxidant capacity, and a lower cadmium content. Instrumental analysis of color, texture, and roughness indicated significant differences between SCG and cocoa muffins, influenced by their different chemical compositions. However, replacing SCG in cocoa muffins is feasible as results from the sensory analysis revealed no statistically significant differences between muffins made with SCG and those made with cocoa on preference and across key attributes, including appearance, flavor, texture, graininess, and bitterness. As expected, muffins with SCG showed a significantly higher score for coffee flavor but a comparable perception of cocoa flavor, despite lacking cocoa in the muffin formulation. These findings underscore the potential of SCG as a viable and sustainable cocoa-replacing flavoring ingredient in baked goods, supporting improved nutritional value, reduced unhealthy cadmium consumption, waste reduction, and product innovation in the food industry.