Figures & data
Figure 1 Schematic diagram of the experimental set-up.
Figure 2 Roasting temperature vs. time.
Figure 3 (a) Calculated transient surface heat flux of the roasted coffee beans. (b) Apparent specific heat of coffee bean powder.
Figure 4 Rate of change in heat of reactions with respect to temperature determined by subtracting the specific heat from the baseline.
Table 1 Temperature region of thermal decomposition of green coffee with corresponding heats of decomposition and activation energies
Figure 5 Calculation procedure for activation energies based on the measured rate of change in heat of reaction.
Figure 6 Pressure drop measured across roasted coffee powder with an absolute pressure cell.
Figure 7 Permeability of the coffee powder during roasting estimated according to Darcy's rule.
