Chemical composition, aroma profile, antioxidant activity, and sensory attributes of beer according to roasting degree and malt type

This study examined the effects of malt roasting degree on the chemical composition, aroma profile, antioxidant activity, and sensory attributes of brewed beer. Roasting increased carbohydrate content, diastatic power, and Maillard products such as melanoidins and Amadori compounds, contributing to deeper color and enhanced antioxidant activity. Aroma profiling with an electronic nose revealed that roasting shifted key volatile classes, including esters, terpenes, pyrazines, and sulfur compounds. Light malt beer retained fruity esters (for example, ethyl hexanoate and cis-3-hexenyl acetate), whereas dark malt beer was enriched in Maillard-derived pyrazines and aldehydes (for example, 2,3-dimethylpyrazine, furfural, maltol) that impart roasted and caramelized notes. Liquid malt beer showed the greatest loss of monoterpenes (for example, γ-terpinene), indicating thermal degradation. These changes aligned with antioxidant capacity, as melanoidin- and pyrazine-rich profiles enhanced radical scavenging. Overall, roasting modulated sensory and antioxidant properties through Maillard-derived transformations, underscoring their impact on beer quality.