Cocoa beans roasting

Roasting is the most important technological operation in cocoa beans processing, and the degree of chemical changes depends on the temperature applied during the process.

Cocoa beans (Theobroma cacao L.) roasting modifies the precursor compounds of flavor and aromas of origin, those formed during fermentation and drying. Roasting is an important heat treatment that is usually accomplished to develop color, characteristic flavor as well as the palatability of food product. These treatments are considered to produce high quality cocoa beans and cocoa butter.

Roasting involves complex chemical transformations, attributed to Maillard reactions, caramelization of sugars, protein degradation, and synthesis of sulfur compounds.

High temperatures and low moisture contents are the ideal conditions for the Maillard reaction and these conditions can be found in suitable roasting method. Roasting parameters varies from 120 to 250 °C for 10 to 120 minutes depending on the color, flavor, texture and application desired. Nib roasting takes up to 60 min and up to 120 min for whole beans roasting of cocoa beans.

During roasting, some compounds increase in concentration, the volatile fraction decreases, and new compounds are formed. Moisture loss and chemical reactions suffered by the beans in the roasting process affect the color, volume, mass, shape, bead pop, pH, density, and especially volatile compounds and flavor.

Properties of roasted beans, such as formation of a characteristic brown color, texture of roasted beans, concentration of volatile flavor compounds, total acidity and fat content, depend on roasting conditions mainly temperature and processing time.
Cocoa beans roasting