IMPACT OF DIFFERENT ROASTING TEMPERATURES ON THE CHEMICAL COMPOSITION, CAFFEINE CONTENT, ACRYLAMIDE CONTENT, PHENOLIC CONTENT, AND ANTIOXIDANT POTENTIAL OF ROBUSTA COFFEE

Ezz, Nader A.M.; Soliman, Abdalrahman M. A.; Toliba, Abbas O.; Alarabi, Ghada M.

doi:10.21608/zjar.2025.465673

IMPACT OF DIFFERENT ROASTING TEMPERATURES ON THE CHEMICAL COMPOSITION, CAFFEINE CONTENT, ACRYLAMIDE CONTENT, PHENOLIC CONTENT, AND ANTIOXIDANT POTENTIAL OF ROBUSTA COFFEE

Document Type : Original Article

Authors

Food Sci.Dept., Fac. Agric., Zagazig Univ., Egypt

10.21608/zjar.2025.465673

Abstract

The chemical composition, caffeine content, acrylamide content, phenolic content, antioxidant potential, browning index, and volatile compound separation using GC–MS were investigated in this study for the three most popular roasting temperatures of Robusta coffee: light (210 ºC; 20 min), medium (230 ºC; 20 min), and dark (240 ºC; 20 min). Light-roasted coffee scored the highest in moisture content and crude protein and the lowest in ether extract and crude fibre, all of which were significant (p < 0.05). With the exception of quercetin, the roasting procedure—specifically, dark roasting—has decreased the levels of kaempferol, caffeine, trigonelline, and hydroxymethylfurfural in both green and roasted coffee samples. Acrylamide levels were lowest in medium-roasted coffee (0.44 mg/100 g) and highest in light-roasted coffee (0.55 mg/100 g). The browning index rises with rising roasting temperature. Light-roasted coffee showed the highest free total phenolic content, the lowest DPPH activity, and the lowest levels of condensed tannins and flavonoid compounds. 126 volatile compounds were discovered and semi-quantified in the dark-roasted coffee using GC-MS. All things considered, this study showed that although rigorous roasting would reduce the quantity of phenolic compounds in coffee beans, it would maintain or even boost their antioxidant capacity. Commercial light-roasted coffee beans have relatively better nutritional value. Our findings may help resolve past disputes and provide useful proof for coffee production in the food sector..

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