Sensory and Physicochemical Characteristics of Two Common Roast Defects in Robusta Coffee

Wenny B Sunarharum, Tunjung Mahatmanto, Dego Y Ali, Yuniar P Prananto, Novianus Efrat, Ngesti E Asih, Nindya G Mirillia


Roasting is an important coffee processing step to generate coffee aroma and flavor. Because roasting is time-temperature dependent, the variation of time and temperature applied may influence the structural properties, visual appearance, and chemistry of coffee. Improper roasting creates roast defects that reduce coffee quality and acceptance. Despite this importance, studies on coffee roast defects, particularly in Robusta coffee is limited. This study aims to characterize two common roast defects, i.e., underdeveloped and overdeveloped, compared with medium roast in Robusta coffee. Sensory evaluation by trained panelists and physicochemical evaluation reveal that the two common roast defect in Robusta coffee can be distinguished clearly through differences in sensory (aroma defect) characteristics as well as physicochemical properties. The overdeveloped roast defect produced darker coffee with the highest pH and total dissolve solids (TDS), and can be characterized by pyridine, furan, phenol and pyrrole derivatives. The carbony and ashy notes of the overdeveloped coffee were potentially contributed by phenol and polyphenol derivatives. In contrast to the overdeveloped coffee, the underdeveloped coffee is markedly characterized by higher concentration of aliphatic acids and higher concentration of pyrazines that contributes to raw nut-like notes. The combination of time and temperature during roasting influences the breakdown of chemical compounds through complex mechanisms involving proteins, carbohydrates and polyphenols degradation. Thus, roasting process variations that determine coffee cup quality and in turn drive consumer acceptance should be controlled.


Aroma; coffee; roasting defect; sensory; volatile.

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ICO, “Coffee year production by country,†2020. [Online]. Available:

W. B. Sunarharum, K. Fibrianto, S. S. Yuwono, and M. Nur, Sains Kopi Indonesia. Malang: UB Press, 2019. pp. 7-9.

W. B. Sunarharum, D. J. Williams, and H. E. Smyth, “Complexity of coffee flavor: A compositional and sensory perspective,†Food Research International, vol. 62. Elsevier Ltd, pp. 315–325, 2014, doi: 10.1016/j.foodres.2014.02.030.

A. Hameed, S. A. Hussain, M. U. Ijaz, S. Ullah, and I. Pasha, “Farm to Consumer : Factors Affecting the Organoleptic Characteristics of Coffee . II : Postharvest Processing Factors,†vol. 17, 2018, doi: 10.1111/1541-4337.12365.

A. T. Toci, D. A. Azevedo, and A. Farah, “Effect of roasting speed on the volatile composition of coffees with different cup quality,†Food Res. Int., vol. 137, Nov. 2020, doi: 10.1016/j.foodres.2020.109546.

S. Schenker, S. Handschin, B. Frey, R. Perren, and F. Escher, “Pore structure of coffee beans affected by roasting conditions,†J. Food Sci., vol. 65, no. 3, pp. 452–457, 2000, doi: 10.1111/j.1365-2621.2000.tb16026.x.

N. Yang, C. Liu, X. Liu, T. K. Degn, M. Munchow, and I. Fisk, “Determination of volatile marker compounds of common coffee roast defects,†Food Chem., vol. 211, pp. 206–214, Nov. 2016, doi: 10.1016/j.foodchem.2016.04.124.

D. Pramudita, T. Araki, Y. Sagara, and A. H. Tambunan, “Roasting and Colouring Curves for Coffee Beans with Broad Time-Temperature Variations,†2017, doi: 10.1007/s11947-017-1912-5.

N. Z. Rao, M. Fuller, and M. D. Grim, “Physiochemical characteristics of hot and cold brew coffee chemistry: The effects of roast level and brewing temperature on compound extraction,†Foods, vol. 9, no. 7, pp. 1–12, 2020, doi: 10.3390/foods9070902.

G. Hu et al., “Effect of roasting degree of coffee beans on sensory evaluation: Research from the perspective of major chemical ingredients,†Food Chem., vol. 331, no. January 2020, doi: 10.1016/j.foodchem.2020.127329.

G. V de Melo Pereira et al., “Exploring the impacts of post-harvest processing on the aroma formation of coffee beans – a review,†Food Chem., vol. 272, pp. 441–452, 2019, doi:

L. Poisson, N. Auzanneau, F. Mestdagh, I. Blank, and T. Davidek, “New Insight into the Role of Sucrose in the Generation of α-Diketones upon Coffee Roasting,†Journal of Agricultural and Food Chemistry, vol. 66, no. 10. pp. 2422–2431, 2018, doi: 10.1021/acs.jafc.6b04849.

A. Anisa, W. K. Solomon, and A. Solomon, “Optimization of roasting time and temperature for brewed hararghe coffee (Coffea Arabica L .) using central composite design,†Int. Food Res. J., vol. 24 (6), no. December, pp. 2285–2294, 2017.

M. A. Schouten, S. Tappi, and S. Romani, “Acrylamide in coffee: formation and possible mitigation strategies – a review,†Crit. Rev. Food Sci. Nutr., vol. 60, no. 22, pp. 3807–3821, Dec. 2020, doi: 10.1080/10408398.2019.1708264.

D. Giacalone, T. K. Degn, N. Yang, C. Liu, I. Fisk, and M. Münchow, “Common roasting defects in coffee: Aroma composition, sensory characterization and consumer perception,†Food Qual. Prefer., vol. 71, pp. 463–474, Jan. 2019, doi: 10.1016/j.foodqual.2018.03.009.

N. Bhumiratana, K. Adhikari, and E. Chambers, “Evolution of sensory aroma attributes from coffee beans to brewed coffee,†LWT - Food Sci. Technol., vol. 44, no. 10, pp. 2185–2192, 2011, doi: 10.1016/j.lwt.2011.07.001.

L. M. Hamilton and J. Lahne, “Assessment of instructions on panelist cognitive framework and free sorting task results: A case study of cold brew coffee,†Food Qual. Prefer., vol. 83, no. August 2019, p. 103889, 2020, doi: 10.1016/j.foodqual.2020.103889.

J. Baggenstoss, L. Poisson, R. Kaegi, R. Perren, and F. Escher, “Coffee Roasting and Aroma Formation: Application of Different Time-Temperature Conditions,†J. Agric. Food Chem., vol. 56, pp. 5836–5846, 2008, doi: 10.1021/jf800327j.

C. N. Cain et al., “Analytical Determination of the Severity of Potato Taste Defect in Roasted East African Arabica Coffee,†J. Agric. Food Chem., vol. 69, no. 7, pp. 2253–2261, Feb. 2021, doi: 10.1021/acs.jafc.1c00605.

E. Bary, “Coffee delivery from indie shops is surging amid COVID-19, new data show,†2020.

M. Münchow, J. Alstrup, I. Steen, and D. Giacalone, “Roasting conditions and coffee flavor: A multi-study empirical investigation,†Beverages, vol. 6, no. 2, pp. 1–14, Jun. 2020, doi: 10.3390/beverages6020029.

J. S. Cho, H. J. Bae, B. K. Cho, and K. D. Moon, “Qualitative properties of roasting defect beans and development of its classification methods by hyperspectral imaging technology,†Food Chem., vol. 220, pp. 505–509, Apr. 2017, doi: 10.1016/j.foodchem.2016.09.189.

H. T. Lawless and H. Heymann, Sensory Evaluation of Food: Principles and Practices. New York: Chapman & Hall, 1998.

A. Abdelwareth, A. Zayed, and M. A. Farag, “Chemometrics-based aroma profiling for revealing origin, roasting indices, and brewing method in coffee seeds and its commercial blends in the Middle East.,†Food Chem., vol. 349, p. 129162, 2021, doi: 10.1016/j.foodchem.2021.129162.

K. Williamson and E. Hatzakis, “Evaluating the e ff ect of roasting on co ff ee lipids using a hybrid targeted- untargeted NMR approach in combination with MRI,†Food Chem., vol. 299, no. July, p. 125039, 2019, doi: 10.1016/j.foodchem.2019.125039.

I. Steen, S. S. Waehrens, M. A. Petersen, M. Münchow, and W. L. P. Bredie, “Influence of serving temperature on flavour perception and release of Bourbon Caturra coffee,†Food Chem., vol. 219, pp. 61–68, 2017, doi: 10.1016/j.foodchem.2016.09.113.

I. Kim et al., “Physicochemical characteristics of Ethiopian Coffea arabica cv. Heirloom coffee extracts with various roasting conditions,†Food Sci. Biotechnol., vol. 30, no. 2, pp. 235–244, 2021, doi: 10.1007/s10068-020-00865-w.

M. Ginz, H. H. Balzer, A. G. W. Bradbury, and H. G. Maier, “Formation of aliphatic acids by carbohydrate degradation during roasting of coffee,†Eur. Food Res. Technol., vol. 211, no. 6, pp. 404–410, 2000, doi: 10.1007/s002170000215.

M. Weers, H. Balzer, A. Bradbury, and O. G. Vitzthum, “Analysis of acids in coffee by capillary electrophoresis,†in Association Scientifique Internationale du Café (ASIC) Paris (ed). 16th International Scientific Colloquium on Coffee, Kyoto 9.4.-14.4.1995, 1995, pp. 218–223.

L. A. Mielby et al., “See, feel, taste: The influence of receptacle colour and weight on the evaluation of flavoured carbonated beverages,†Foods, vol. 7, no. 8, Aug. 2018, doi: 10.3390/foods7080119.

F. M. Carvalho and C. Spence, “Cup colour influences consumers’ expectations and experience on tasting specialty coffee,†Food Qual. Prefer., vol. 75, pp. 157–169, Jul. 2019, doi: 10.1016/j.foodqual.2019.03.001.

M. J. Higgins and J. E. Hayes, “Learned color taste associations in a repeated brief exposure paradigm,†Food Qual. Prefer., vol. 71, pp. 354–365, Jan. 2019, doi: 10.1016/j.foodqual.2018.08.013.

N. Dulsat-Serra, B. Quintanilla-Casas, and S. Vichi, “Volatile thiols in coffee: A review on their formation, degradation, assessment and influence on coffee sensory quality,†Food Res. Int., vol. 89, pp. 982–988, Nov. 2016, doi: 10.1016/j.foodres.2016.02.008.

J. K. Moon and T. Shibamoto, “Role of roasting conditions in the profile of volatile flavor chemicals formed from coffee beans,†J. Agric. Food Chem., vol. 57, no. 13, pp. 5823–5831, 2009, doi: 10.1021/jf901136e.

N. Caporaso, M. B. Whitworth, C. Cui, and I. D. Fisk, “Variability of single bean coffee volatile compounds of Arabica and robusta roasted coffees analysed by SPME-GC-MS,†Food Res. Int., vol. 108, pp. 628–640, 2018, doi:

M. Haile, H. M. Bae, and W. H. Kang, “Comparison of the Antioxidant Activities and Volatile Compounds of Co ff ee Beans Obtained Using Digestive Bio-Processing (Elephant Dung Coffee) and Commonly Known Processing Methods,†2020.

M. Fakih, K. Nuri, and N. Wulandari, “Metabolomic approach for understanding phenolic compounds and melanoidin roles on antioxidant activity of Indonesia robusta and arabica coffee extracts,†Food Sci. Biotechnol., 2017, doi: 10.1007/s10068-017-0228-6.

N. Caporaso, M. B. Whitworth, C. Cui, and I. D. Fisk, “Variability of single bean coffee volatile compounds of Arabica and robusta roasted coffees analysed by SPME-GC-MS,†Food Res. Int., vol. 108, pp. 628–640, 2018, doi: 10.1016/j.foodres.2018.03.077.

F. B. Mortzfeld, C. Hashem, K. Vranková, M. Winkler, and F. Rudroff, “Pyrazines: Synthesis and Industrial Application of these Valuable Flavor and Fragrance Compounds,†Biotechnology Journal, vol. 15, no. 11. Wiley-VCH Verlag, Nov. 01, 2020, doi: 10.1002/biot.202000064.

I. Blank, A. Sen, and W. Grosch, “Potent odorants of the roasted powder and brew of Arabica coffee,†Z. Lebensm. Unters. Forsch., vol. 195, no. 3, pp. 239–245, 1992, doi: 10.1007/BF01202802.



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