Kinetics of mass loss of arabica coffee during roasting process

 

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Bibliographic Details
Authors: Vargas Elías, Guillermo Asdrúbal, Corrêa, Paulo Cesar, De Souza, Natália R., Baptestini, Fernanda M., De C. Melo, Evandro
Format: artículo original
Publication Date:2016
Description:Roasting is one of the most complex coffee processing steps due to simultaneous transfers of heat and mass. During this process, beans lose mass because of fast physical and chemical changes that will set color and flavor of the commercial coffee beverage. Therefore, we aimed at assessing the kinetics of mass loss in commercially roasted coffee beans according to heating throughout the processing. For that, we used samples of 350-g Arabica coffee processed grains with water content of 0.1217 kga kg-1, in addition to a continuous roaster with firing gas. The roaster had initial temperatures of 285, 325, 345 and 380 °C, decreasing during the process up to 255, 285, 305 and 335 °C respectively. Mass loss was calculated by the difference between grain weight before and after roasting. We observed a linear variation directly dependent on roaster temperature. For each temperature during the process was obtained a constant mass loss rate, which was reported by the Arrhenius model with r2 above 0.98. In a roaster in non-isothermal conditions, the required activation energy to start the mass loss in a commercial coffee roasting index was 52.27 kJ mol -1.
Country:Kérwá
Institution:Universidad de Costa Rica
Repositorio:Kérwá
OAI Identifier:oai:kerwa.ucr.ac.cr:10669/72994
Online Access:http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162016000200300&lng=en&tlng=en
https://hdl.handle.net/10669/72994
Keyword:Coffea arabica
Mass decrease
Roasting degree
Roasting temperature
Non-isothermal roasting