Fate of flavonoids and theobromine in cocoa beans during roasting: Effect of time and temperature

The content of phenolic compounds in chocolate depends on the processing of the cocoa from bean to bar. The aim of this study was to determine the fate of phenolic compounds and theobromine in cocoa beans during roasting at different temperatures. Based on a screening of 12 cocoa bean sorts, three beans (NM, NCC, and NB) with initial high total phenolic content (TPC) were selected for the roasting trial (100 and 150°C up to 20 min). The concentration of three major flavonoids ((−)-catechin, (−)-epicatechin and procyanidin B2) and one methylxanthine (theobromine) were evaluated in both raw and roasted beans. Results showed changes in the concentration of flavonoids and theobromine during roasting. Roasting at 150°C for 15 min was optimal for maintaining high flavonoid levels while reducing theobromine levels. However, sensory evaluation on final product is needed to confirm whether the suggested roasting condition would also result in a final product with pleasant sensory properties.