Milk minimizes sensory penalties in coffee pulp infusions more effectively than rice and soy beverages

Coffee pulp (Coffea arabica L.), authorized in the EFSA as a traditional food from a third country under the novel food framework, is a bioactive by-product with potential for sustainable beverage development. Although its extraction and bioaccessibility have been optimized in dairy and plant-based matrices, consumer acceptance of these formulations remains unexplored.

A pilot consumer study involving thirty-three target consumers, all self-reported users and likers of coffee and/or tea products, evaluated an optimized coffee pulp infusion prepared at 0.08 g/mL for 9 min and formulated with reduced-fat milk, rice beverage, soy beverage, or water as a control, according to a balanced Williams Latin square design. Samples were maintained at 65 °C until serving. No panelist or serving order effects were detected (p > 0.05).

Overall liking did not differ significantly among formulations (p > 0.05); however, purchase intent showed marked differences, with positive responses of 48%, 45%, 45%, and 21% for control, milk, rice, and soy formulations, respectively. RATA profiling showed that milk and soy reduced perceived acidity compared with the control and rice formulations, whereas only milk reduced astringency to levels comparable to the ideal product. Consistently, mean drop analysis based on five-point JAR scales identified no significant sensory penalties in the milk formulation, while rice was penalized for excessive aftertaste (mean drop: −1.98) and soy for excessive aftertaste (−2.25), insufficient aroma (−1.28), and insufficient sweetness (−1.95). Instrumental analyses supported these findings: milk and soy increased pH (4.36 and 4.23 compared with 3.82 in the control) and turbidity, contributing to perceived acidity masking. Finally, the first two principal components explained 84.1% of total variance and revealed a persistent aromatic gap between formulations and the ideal product.

Among the tested matrices, milk was the most effective for coffee pulp valorization, reducing acidity and astringency without generating sensory penalties. Although soy mimicked several physicochemical properties of milk, its sensory profile substantially reduced purchase intent. Aroma enhancement emerged as the main target for future product optimization.