Optimization of Roasting Conditions for High-Quality Robusta Coffee

Central Composite Design (CCD) was used to optimise temperature and time of Robusta coffee beans roasting. Current method of roasting was able to give good quality beans in term of flavour but the formation of acrylamide was not studied. In this study, optimization was based on high quantity of flavour compounds (pyrazines) with low level of acrylamide resulted in roasting temperature and time of 180 °C and 26 minutes, respectively. The coffee beans produced using the optimized conditions have the following characteristics: colour; L* 10.47-15.45, a* 2.78-4.69and b* 6.11-10.95; flavour compounds: 2,3,5 trimethyl pyrazine (0.832 mg/100 g), 2,3 dimethyl pyrazine (1.69 mg/100 g), 2 methyl pyrazine (0.49 mg/100 g) and 2,5 dimethyl pyrazine (0.62 mg/100 g) and low concentration of acrylamide (0.23 mg/100 g). This proposed roasting condition will be very useful for coffee manufacturers in order to produce high quality coffee beans.