Optimization of the roasting of robusta coffee (C-canephora conillon) using acceptability tests and RSM

With the objective of optimizing the roasting of robusta coffee (Coffea canephora Conillon), a two factor central composite design (11 samples) was used to optimise the settings for roasting time and the initial internal temperature of the roaster drum on response variables of acceptance with 25 consuming assessors, for the sensory attributes of beverage aroma, flavour and colour. Predictive models were also obtained for the instrumental measurement of the colour of the beans and ground coffee. The optimum range for roasting was shown to be a time of 22-28 min at a temperature of 225-230 degreesC, corresponding to the degree of roasting characterized by the following range of colour of roasted robusta beans: L* between 37.05 and 40.69, a* between 2.29 and 4.15 and b* between 2.70 and 6.29. (C) 2001 Published by Elsevier Science Ltd.