A Kinetics and Modeling Study of Coffee Roasting Under Isothermal Conditions

作者：Wang Xiuju; Lim Loong Tak^*

来源：Food and Bioprocess Technology, 2014, 7(3): 621-632.

DOI：10.1007/s11947-013-1159-8

• Isothermal coffee roasting
• Lightness
• Roast loss
• Volatile compounds
• Kinetics modeling

In this study, changes in lightness, roast loss, residual CO2, and total volatiles of an Arabica coffee were investigated under isothermal conditions at 220, 230, 240, and 250 A degrees C. The lightness of the roasted coffee, expressed as L* value, followed two-stage processes that could be modeled using pseudo first-order reaction models, giving activation energies of 59.7 and 170.2 kJ/mol for the first and second stages, respectively. Roast loss data also exhibited two-stage behavior, but followed zero-order reaction kinetics, with activation energies of 52.9 and 181.3 kJ/mol for the first and second stage, respectively. The first-to-second stage transition for L* value and roast loss occurred at light-medium roast. Residual CO2 in the coffee beans correlated negatively with L* value below medium-dark roast degree. However, a reversed correlation was observed above dark roast degree. The volatile compounds generated in roasted coffee were highly dependent on roasting temperature and roast degree.

• 出版日期2014-3