Roasted black barley as a partial substitute for decaffeinated coffee: physicochemical properties, volatile profiles, and sensory acceptance

This study evaluated candidate formulations for a novel low-caffeine beverage by blending decaffeinated coffee (D) and black barley (B). The diverse characteristics and sensory evaluations of roasted blends were comprehensively analyzed. B was caffeine-free and exhibited a similar color to coffee and a higher true density, which could compensate for the reduced density of D, though it was distinguished as a different beverage. The physicochemical and flavor attributes of the blended generally followed a linear trend according to the blending ratios. Notably, the D7B3 formulation (70% D and 30% B) could be the most promising matrix. D7B3 closely resembled D in color and true density while maintaining antioxidant activities and relative volatile profiles, with a further reduction of caffeine content. Sensory evaluations confirmed that D7B3 achieved a significantly higher overall acceptance than D5B5 (50% D and 50% B; p < 0.05). Consequently, substituting 30% of D with black barley can provide a viable formulation that maintains coffee-like attributes.