Sensory profile of Italian Espresso brewed Arabica Specialty Coffee under three roasting profiles with chemical and safety insight on roasted beans

Specialty coffee (SC) has been showing an increasing interest from the consumers which appreciate its traceability and the peculiar flavours from each single origin. Additionally, the processes to which coffee fruits underwent to get green coffee characterise the beans in terms of macromolecules acting as substrates during the roasting. This work evaluates via sensory analysed eight SC, roasted at light, medium, and dark level, submitted to Italian espresso extraction, to assess how different roasting levels exalt the expected cup profile obtained by the suppliers via cupping in origin countries. Finally, roasted beans were characterised for physico-chemical features (pH, titratable acidity, caffeine, melanoidins, polyphenols and acrylamide). Sensory analysis demonstrated that the intermediate roasting level and espresso extraction match better attributes from in-origin cupping. Melanoidins (mmol g⁻¹ coffee d.b.) was able to discriminate among roasting levels (light 0.12 ± 0.01; medium 0.13 ± 0.003; dark 0.14 ± 0.01; α = 0.05). Acrylamide analyses ensured compliance with the food safety standards (light 301.9 ± 37.2 ppb; medium 126.1±19ppb; dark 107.9 ± 22.5ppb). Physico-chemical features were able to cluster samples from different origins within the same roasting level (α = 0.05). Results showed correlations (α = 0.01) between sensory analysis and physico-chemical values: direct for caffeine and astringency, reverse for perceived acidity in relation to astringency, roasted, dried fruits and nutty notes.