• MILTON MUÑOZ Universidad Industrial de Santander, UIS Escuela de Ingeniería Eléctrica, Electrónica y Telecomunicaciones, E3T
  • MANUEL ROA Universidad Industrial de Santander, UIS Escuela de Ingeniería Metalúrgica y Ciencia de Materiales
  • RODRIGO CORREA Universidad Industrial de Santander, UIS Escuela de Ingeniería Eléctrica, Electrónica y Telecomunicaciones, E3T




Coffee drying, thermogravimetric analysis, diffusion coefficient, global optimization


 This article presents the main results of thermal analytical and drying tests applied to the endocarp of coffee bean samples, in order to analyze their influence on the coffee dehydration process. An infrared analysis, as well as TGA, DTGA and DSC tests, were applied to the parchment of a sample of Castilla variety coffee beans and later compared with similar tests performed on coffee beans of the same variety, upon parchment removal. For analytical tests, the main thermogravimetric transitions are reported up to a temperature of 1000 °C. From thermograms, four temperature range were identified for parchment, with their respective mass loss: 33-33.7°C, 9.48%; 33.7-251.2°C, 16.23%; 251.2-358°C, 47.48%; and 358-800°C, 15.52%. The greatest mass loss was due to cellulose and hemicellulose degradation. The study was complemented by drying experiments on samples of beans with and without parchment. The diffusion coefficients were found using Fick’s second law and metaheuristic optimization methods (global optimization). On average, the diffusion coefficient of grains without endocarp is 46% greater than that of beans dried with the parchment. Coffee beans with parchment took, on average, 50% more time to reaching moisture levels of 12% (on dry basis). The results are considered important for the projection and design of new coffee drying systems and their automatic control. 


AMARAL et al. Simulation of coffee fruit drying using computational fluid dynamics. Coffee Science, 13(4), 477–488. 2018. Available in: http://www.coffeescience.ufla.br/index.php/Coffeescience/article/view/1489/PDF1489

BEKALO, S. A.; REINHARDT, H. W. Fibers of coffee husk and hulls for the production of particleboard. Materials and Structures/Materiaux et Constructions, 43(8), 1049–1060. 2010. https://doi.org/10.1617/s11527-009-9565-0

BOOT, W. From the cherry to the green bean - post harvesting coffee processing. In Coffee Processing Handbook (pp. 173–192). 2013. Available in: https://bootcampcoffee.com/wp-content/uploads/2013/03/coffeeprocessing-handbook.pdf

CRANK, J. (1975). The Mathematics of Diffusion. Clarendon Press, Oxford 1975. https://doi.org/10.1016/0306-4549(77)90072-X

ESQUIVEL, P.; JIMÉNEZ, V. M. Functional properties of coffee and coffee by-products. Food Research International, 46(2), 488–495. 2012. https://doi.org/10.1016/j.foodres.2011.05.028

FAO. Grain crop drying, handling and storage. Rural Structures in the Tropics: Design and Development, 363–386. 2011. Available in: http://www.fao.org/docrep/015/i2433e/i2433e10.pdf

GHOSH, P. Processing and Drying of Coffee – A Review. International Journal of Engineering Research & Technology, 3(12), 784–794. 2014. https://doi.org/10.1126/science.1115581

HENAO ARISMENDY, J. Evaluación del proceso de secado del café y su relación con las propiedades físicas, composición química y calidad en taza. Universidad Nacional de Colombia Sede Medellín. 2015. Available in: http://www.bdigital.unal.edu.co/51841/1/1128270450.2016.pdf%0Ahttp://www.bdigital.unal.edu.co/51841/

MUÑOZ, M.; ROA, M.; CORREA, R. (2018). Thermal Analysis of Coffee Beans of Castilla Variety Grown in. Revista Mexicana de Ingeniería Química, 17(3). 2018. Available in: http://www.rmiq.org/ojs311/index.php/rmiq/article/view/62

PUERTA, G. Cómo garantizar la buena calidad de la bebida del café y evitar los defectos. Cenicafé, AT284, 8. 2001. Available in: www.cenicafe.org

PUERTA, G. La humedad controlada del grano preserva la calidad del café. Cenicafé, 352, 1–8. 2006. Available in: http://biblioteca.cenicafe.org/bitstream/10778/418/1/avt0352.pdf

RIBEIRO, B. B. et al. Sensory analysis of coffee dried with and without stirring. Coffee Science, 13(4), 455–464. 2018. Available in: http://www.coffeescience.ufla.br/index.php/Coffeescience/article/view/1472/PDF1472

RODRIGUES DE OLIVEIRA, A. P. et al. Thermodynamic properties of drying process and water absorption of rice grains. CyTA - Journal of Food, 15(2), 204–210. 2016. https://doi.org/10.1080/19476337.2016.1238012

RODRÍGUEZ VALENCIA, N.; ZAMBRANO FRANCO, D. Los subproductos del café. Avances Técnicos Cenicafé, (3), 8. 2010. Available in: http://biblioteca.cenicafe.org/bitstream/10778/351/1/avt0393.pdf

VARADHARAJU, N.; KARUNANIDHI, C.; KAILAPPAN, R. Coffee cherry drying: A two-layer model. Drying Technology, 19(3–4), 709–715. 2001. https://doi.org/10.1081/DRT-100103947



How to Cite

MUÑOZ, M.; ROA, M.; CORREA, R. ENDOCARP ANALYSIS OF A TRADITIONAL VARIETY OF COLOMBIAN COFFEE. Coffee Science - ISSN 1984-3909, v. 14, n. 2, p. 206 - 222, 28 Jun. 2019.