Optimization of cocoa beans roasting process using Response Surface Methodology based on concentration of pyrazine and acrylamide

Roasting is an important process that contribute to formation of flavour compounds in cocoa beans. Pyrazines, a by-product of Maillard reaction is one of the character impact compounds that contribute to unique cocoa flavour. Unfortunately during roasting, carcinogenic acrylamide are also produced through Maillard reaction. Therefore, this study was focussed on optimising the roasting conditions using Central Composite Design (CCD) to produce superior quality cocoa beans with high concentration of pyrazines and low concentration of acrylamide. The roasting conditions used were temperatures in the range of 110°C to 160°C and time ranging from 15 min to 40 min. Roasting conditions significantly (p 0.005) affect the concentration of pyrazines in cocoa beans. However, the RSM analysis shows that the concentration of acrylamide in the beans was not influenced by the roasting conditions. Statistical optimisation based on maximum pyrazines and minimum acrylamide at temperature of 116°C and a time of 23 min produced the desirable value of 0.73. Hence, the optimized roasting conditions were able to produce high quality cocoa beans.