Physical and Chemical Properties of Indonesian Coffee Beans for Different Postharvest Processing Methods


  • Elin Yusibani Physics Department, FMIPA, Universitas Syiah Kuala, Jalan Teuku Nyak Arief Darussalam 23111, Indonesia
  • Peter Lloyd Woodfield Griffith School of Engineering and Built Environment, Gold Coast Campus Griffith University, Parklands Dr Southport, Qld 4215, Australia
  • Adi Rahwanto Physics Department, FMIPA, Universitas Syiah Kuala, Jalan Teuku Nyak Arief Darussalam 23111, Indonesia
  • Muhammad Syukri Surbakti Physics Department, FMIPA, Universitas Syiah Kuala, Jalan Teuku Nyak Arief Darussalam 23111, Indonesia
  • Rajibussalim Rajibussalim Physics Department, FMIPA, Universitas Syiah Kuala, Jalan Teuku Nyak Arief Darussalam 23111, Indonesia
  • Rahmi Rahmi Chemistry Department, FMIPA, Universitas Syiah Kuala, Jalan Teuku Nyak Arief Darussalam 23111, Indonesia



coffee, Flores, roasted, Gayo Luwak, Gayo, Kintamani, Toraja, Wamena


The purpose of this study was to identify the physical and chemical properties of Indonesian coffee beans for different postharvesting methods after being roasted. Several types of Indonesian export coffee, i.e., Gayo Luwak coffee, Wamena coffee, Toraja coffee, Gayo coffee, Flores coffee and Kintamani coffee, were used in the present study. Each coffee has its own aroma and taste according to the location, soil type, and land elevation. The roasting process started with preheating the roasting machine, after which the samples were roasted for about 15 minutes at 215? to obtain the medium-to-dark (MTD) roasting level. The physical properties measured included density, mass loss, porosity, water content, and morphology using a scanning electron microscope. The transmittance spectrum was observed by Fourier transform infrared spectroscopy (FTIR). The physical properties of the coffee were successfully measured. The bulk density varied from 0.6 to 0.7 g/cm3, and particle density was about 0.9 g/cm3 for green beans. The roasting process reduced the bulk and particle density to 0.3 g/cm3 on average and 0.8 g/cm3, respectively. The fully-washed condition gave an overlapping spectrum for green and roasted beans, which shows that the roasting process did not affect the spectrum. The results can be used to study the coffee quality resulting from different postharvest processing methods.


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Directorate General for National Export Development Ministry of Trade Republic of Indonesia, Indonesian Coffee, Export News Indonesia, Ditjen PEN/MJL/XXIII/07/2014, 2014.

Gope, H.L. & Fukai, H., Normal and Peaberry Coffee Beans Classification from Green Coffee Bean Images Using Convolutional Neural Networks and Support Vector Machine, International Journal of Computer and Information Engineering, 14(6), pp.189-196, 2020.

Suhandy, D. & Yulia, M., Peaberry Coffee Discrimination using UV-visible Spectroscopy Combined with SIMCA and PLS-DA, International Journal of Food Properties, 20(1), pp. S331-S339, 2017. doi: 10.1080/10942912.2017.1296861.

Clifford, M.N. & Willson, K.C., (eds.), Coffee: Botany, Biochemistry and Production of Beans and Beverage, AVI Publishing Company Inc., Westport, Connecticut, 1985.

Cortez, J.G. & Menezez, H.C., Recent Developments in Brazilian Coffee Quality: New Processing Systems, Beverage Characteristics and Consume Preferences, in Sera, T., Soccol, C.R., Pandey, A. & Roussos, S. (ED)., Coffee Biotechnology and Quality. Proceedings of the 3rd International Seminar on Biotechnology in The Coffee Agroindustry, Londrina, Brazil, pp. 339-346, 2000.

Schenker, S., Handschin, S., Frey, B., Perren, R. & Escher, F., Pore Structure of Coffee Beans Affected by Roasting Conditions, Journal of Food Science, 65(3), pp.452-457, 2000.

Pittia, P., Nicoli, M.C. & Sacchetti, G. Effect of Moisture and Water Activity on Textural Properties of Raw and Roasted Coffee Beans, Journal of Texture Studies, 38, pp. 116-134, 2007.

Kuala, S.I., Hidayat, D.D., Anggara, C.W.E. & Saparita, R., Characterization and Evaluation of Physical and Mechanical Properties of Unhulled Arabica Coffee Bean, IOP Conf. Series: Earth and Environmental Science, 251, 012040, 2019. doi:10.1088/1755-1315/251/1/012040.

Olukunle, O.J. & Akinnuli, B.O., Investigating Some Engineering Properties of Coffee Seeds and Beans, Journal of Emerging Trends in Engineering and Applied Sciences, 3(5), pp.743-747, 2012.

Ismail, I., Anuar, M.S. & Shamsudin, R. Effect on the Physico-Chemical Properties of Liberica Green Coffee Beans Under Ambient Storage, Intern. Food Research J, 20(1) pp. 255-264, 2013.

Thammarat, P., Kulsing, C., Wongravee, K., Leepipatpiboon, N. & Nhujak, T., Identification of Volatile Compounds and Selection of Discriminant Markers for Elephant Dung Coffee Using Static Headspace, Gas Chromatography-Mass Spectrometry and Chemometrics Molecules, 23(8), 1910, 2018. doi: 10.3390/molecules23081910.

Severa, L., Buchar, J. & Nedomov S., Shape and Size Variability of Roasted Arabica Coffee Beans, Intern. J. of Food Properties, 15(2), pp.426-437, 2012. doi: 10.1080/10942912.2010.487967.

Nakilcio?luTa?, E. & le?, S., Physical Characterization of Arabica Ground Coffee with Different Roasting Degrees, Anais da Academia Brasileira de Cicias (Annals of the Brazilian Academy of Sciences), 91(2), e20180191, 2019.

Od?akovi?, B., D?ini?, N., Jokanovi?, M. & Gruji?, S., The Influence of Roasting Temperature on the Physical Properties of Arabica and Robusta Coffee, Acta Periodica Technologica, 50, pp. 172-178, 2019.

Jokanovi?, M.R., D?ini?, N.R., Cvetkovi?, B.R., Gruji?c, S. & Od?akovi?, B., Changes of Physical Properties of Coffee Beans During Roasting, Acta periodica technologica, 43(1-342) pp. 21-31, 2012. doi: 10.2298/APT1243021J.

Baggenstoss, J., Perren, R. & Escher, F., Water Content of Roasted Coffee: Impact on Grinding Behavior, Extraction, and Aroma Retention, Eur. Food Res. Technol., 227(5), pp.1357-1365, 2008. doi: 10.1007/s00217-008-0852-8.

Andueza, S., De Pena, M.P. & Cid, C., Chemical and Sensorial Characteristics of Espresso Coffee as Affected by Grinding and Torrefacto Roast, J. Agric. Food Chem, 51, pp. 7034-7039, 2003.

Ozguven, F. & Vursavus, K., Some Physical, Mechanical and Aerodynamic Properties of Pine Nuts, Journal of Food Engineering, 68, pp. 191-196, 2005.

Krokida, M.K. & Maroulis, Z.B., Structural Properties of Dehydrated Products during Rehydration, Int. J. Food Sci. Technol., 36(5), pp.529-538, 2001.

Fernandes, R.V.B., Borges, S.V. & Botrel, D.A., Influence of Spray Drying Operating Conditions on Microencapsulated Rosemary Essential Oil Properties, Ciencia Tecnol. Alime, 33(1) pp. 171-178, 2013.

Rodrigues, M.A.A., Borges, M., Franca, A., Oliveira, L. & Correa, P., Evaluation of Physical Properties of Coffee during Roasting Agricultural Engineering International: the CIGR Journal of Scientific Research and Development, Presented at the ASAE Annual International Meeting/CIGR XVth World Congress, Chicago, Il. 2002.

National Standardization Bureau, Indonesian National Standard for Coffee Bean, SNI 01-2907-2008, ICS 67.140.20, 2008.

Adekunle, A.A., Shittu, T.A., Abioye, A.O., Adeyanju, J.A. & Osanaiye. F.G., Physical and Thermal Properties of Baobab Fruit Pulp Powder, International Journal of Engineering Research and Applications (IJERA), 3(3) pp. 925- 928, 2013.

ASEAN Standard for Coffee Bean, ASEAN Stan 31: 2013, 2013.

Sivetz, M. & Desrosier, N.W., Coffee Technology, Westport Co, Avi Publishing Co. 1979.

Ameyu, M.A., Physical Quality Analysis of Roasted Arabica Coffee Beans Subjected to Different Harvesting and Postharvest Processing Methods in Eastern Ethiopia, Food Science and Quality Management, 57, 2016.

Clarke, R. J. & Macrae, R., Coffee Vol. 2 Technology, Amsterdam, Elsevier Applied Science, 1987.

Dutra, E.R., Oliveira, L.S., Franca, A.S., Ferraz, V.P. & Afonso, R.J.C., A Preliminary Study on the Feasibility of using the Composition of Coffee Roasting Exhaust Gas for the Determination of the Degree of Roast, Journal of Food Engineering, 47, pp. 241-246. 2001.

Yusibani, E., Putra, R.I, Rahwanto, A. & Surbakti, M.S., Rajibussalim & Rahmi, Physical Properties of Sidikalang Robusta Coffee Beans Medium Roasted from Various Colors of Coffee Cherries, J. Phys.: Conf. Ser., 2243, 012046. 2021. doi: 10.1088/1742-6596/2243/1/012046.

Ortega-Rivas, E., Bulk Properties of Food Particulate Materials: An Appraisal of Their Characterization and Relevance in Processing Food, Bioprocess Tech, 2(1) pp.28-44, 2009.

Oliveros, N.O., Herndez, J.A., Sierra-Espinosa, F.Z., Guardi, R., Tapia, R. & Solzano, P., Experimental Study of Dynamic Porosity and Its Effects on Simulation of the Coffee Beans Roasting, Journal of Food Engineering, 199, pp. 100-112, 2017.

Schenker, S. & Rothgeb, T., The Craft and Science of Coffee, Chapter 11 The Roast-Creating the Beans' Signature, pp 245-271, 2017. doi:10.1016/B978-0-12-803520-7.00011-6.

Kanai, N., Yoshihara, N. & Kawamura, I., Solid-State NMR Characterization of Triacylglycerol and Polysaccharides in Coffee Beans, Bioscience Biotechnology Biochemistry, 83, pp. 803-809, 2019

Bellamy, L.J., The Infrared Spectra of Complex Molecules; 3rd ed.; Chapman & Hall Ltd.: London, England, 1, 1975.

Kemsley, E.K., Ruault, S. & Wilson, R.H., Discrimination Between Coffea Arabica and Coffea Canephora Variant Robusta Beans Using Infrared Spectroscopy, Food Chemistry, 54, pp. 321-326, 1995. doi: 10.1016/0308-8146(95)00030-M.

Lyman, D. J., Benck, R., Dell, S., Merle, S. & Murray-Wijelath, J., FTIR-ATR Analysis of Brewed Coffee: Effect of Roasting Conditions, Journal of Agricultural and Food Chemistry, 51, pp. 3268?3272. 2003. doi: 10.1021/jf0209793.

Wang, J., Jun, S., Bittenbender, H.C., Gautz, L. & Li, Q.X., Fourier Transform Infrared Spectroscopy for Kona Coffee Authentication, Journal of Food Science, 74, pp. C385-C391, 2009.

Singh, B.R., Wechter, M.A., Hu, Y. & Lafontaine, C., Determination of Caffeine Content in Coffee Using Fourier Transform Infra-Red Spectroscopy in Combination with Attenuated Total Reflectance Technique: A Bioanalytical Chemistry Experiment for Biochemists, Biochemical Education, 26, pp. 243-247, 1998.

Ribeiro, J.S., Salva, T.J. & Ferreira, M.M., Chemometric Studies for Quality Control of Processed Brazilian Coffees Using DRIFTS, Journal of Food Quality, 33, pp. 212-227, 2010.




How to Cite

Yusibani, E., Woodfield, P. L., Rahwanto, A., Surbakti, M. S., Rajibussalim, R., & Rahmi, R. (2023). Physical and Chemical Properties of Indonesian Coffee Beans for Different Postharvest Processing Methods. Journal of Engineering and Technological Sciences, 55(1), 1-11.




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