Korean Journal of Food Science and Technology (한국식품과학회지)

Korean Society of Food Science and Technology (한국식품과학회)
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Analysis of Off-flavor Compounds from Over-extracted Coffee

과추출에 의한 커피의 이취성분 분석

  • Lee, Jin-Sung (Department of Food Science and Technology, Chung-Ang University) ;
  • Kim, Min-Sun (Department of Food Science and Technology, Chung-Ang University) ;
  • Shin, Ho-Jae (Chemical Assessment Team, R&D Center Maeil Dairies Co., Ltd.) ;
  • Park, Ki-Hwan (Department of Food Science and Technology, Chung-Ang University)
  • 이진성 (중앙대학교 식품공학과) ;
  • 김민선 (중앙대학교 식품공학과) ;
  • 신호재 (매일유업 중앙연구소 식품분석연구) ;
  • 박기환 (중앙대학교 식품공학과)
  • Received : 2011.03.07
  • Accepted : 2011.03.31
  • Published : 2011.06.30
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Abstract

To verify the volatile compounds contributing to coffee off-flavor, medium roasted Colombian, Sumatra, Ethiopian and light and dark roasted Colombian bean coffees were sequentially and studiously over extracted. Eight espresso samples and eight filter-dripped samples were analyzed by gas chromatography/mass spectrometry with the solidphase microextraction method and evaluated by sensory tests. In total, 67 compounds were detected, and desirable aroma decreased sharply, while off-flavors increased rapidly after 30 mL of espresso and 200 mL of drip coffee. Percent peak area of 4-ethylguaiacol revealed a linear increase during extraction and was highly correlated with increasing off-flavor, suggesting that it could be an indicator of over extraction. Considering the odor activity value, guaiacol and 4- vinylguaiacol were also contributory compounds to off-flavors.

연속적으로 추출한 커피액을 단계별로 일정량 취하여 관능검사를 실행한 결과 고형분의 함량을 시료별로 동일하게 희석하였음에도 에스프레소 추출의 경우 30 mL 이상, 드립커피에서는 200mL 이상 추출한 경우 향미는 감소하고 이취는 증가하여 과추출이 시작됨을 인지할 수 있었다. 이는 추출 단계별로 고형분 성분의 조성비의 변화가 있음을 의미하며 GC/MS로 성분비의 변화를 확인한 결과 4-ethylguaiacol은 통계분석 시 이취에 높은 상관관계를 보여주는 유효 향기성분인 동시에 커피의 재료, 배전도, 추출 방식에 상관없이 추출이 경과함에 따라 성분비가 직선에 가까운 상승비를 보이므로 과추출을 나타내는 지표 물질로 사용할 수 있음을 보여 주었다. Guaiacol과 4-vinylguaiacol은 이취와 통계적으로 높은 연관성을 보인 4-ethylguaiacol에 비해 향기 인지에 큰 영향을 미치는 ordor threshold value가 낮고 피크 면적 %는 큰 차이를 보이지 않으므로 과추출로 인한 이취에 큰 영향을 미치는 것으로 여겨진다. 이들 성분이 과추출 인지점 이후 증가하는 피크 면적 %를 보이는 것은 세포벽을 구성하는 섬유질의 탄 맛이 일정량 계속 침출되기 때문으로 보인다. 인스턴트커피 및 농축 커피 용액 제조 시 관능검사 결과와 함께 GC/MS로 4-ethylguaiacol의 피크 면적 %결과를 비교 분석하면 용액의 추출수율과 관능적 품질 선호도 즉 경제성과 품질을 최적화할 수 있는 지표로 사용할 수 있을 것이다.

Keywords

References

  1. Navarini L, Rivetti D. Water quality for Espresso coffee. Food Chem. 122: 424-428 (2010) https://doi.org/10.1016/j.foodchem.2009.04.019
  2. Bersten I. Coffee Floats Tea Sinks. Helian Books, Roseville, Australia. pp. 59-98 (1993)
  3. Petracco M. Percolation. p. 265, 285, 303. In: Espresso Coffee 2nd ed. Illy A, Viani R. (eds) Elsevier Academic Press, London, UK (2005)
  4. Andueza S, Vila MA, de Pena MP. Influence of coffee/water ratio on the final quality of Espresso coffee. J. Sci. Food Agr. 87: 586- 592 (2007) https://doi.org/10.1002/jsfa.2720
  5. Flament I. Coffee Flavor Chemistry. John Wiley & Sons, Ltd. Chichester, West Sussex, England. p. 74, 115 (2002)
  6. Semmelroch P, Grosch W. Analysis of roasted coffee powders and brews by mgas chromatography-olfactometry of headspace samples. Lebensm.-Wiss. Technol. 28: 310-313 (1995) https://doi.org/10.1016/S0023-6438(95)94411-7
  7. Semmelroch P, Grosch W. Studies on character odorants of coffee brews. J. Agr. Food Chem. 44: 537-543 (1996) https://doi.org/10.1021/jf9505988
  8. Czerny M, Mayer F, Grosch W. Sensory study on the character impact odorants of roasted arabica coffee. J. Agr. Food Chem. 47: 695-699 (1999) https://doi.org/10.1021/jf980759i
  9. Czerny M, Grosch W. Potent odorants of raw arabica coffee: Their changes during roasting. J. Agr. Food Chem. 48: 868-872 (2000) https://doi.org/10.1021/jf990609n
  10. Mayer F, Czerny M, Grosch W. Sensory study of the character impact aroma compounds of a coffee beverage. Eur. Food Res. Technol. 211: 272-276 (2000) https://doi.org/10.1007/s002170000169
  11. Mayer F, Grosch W. Aroma simulation on the basis of the odourant composition of roasted coffee headspace. Flavour Frag. J. 16: 180-190 (2001) https://doi.org/10.1002/ffj.975
  12. Acree TE, Barnard J, Cunningham DG. A procedure for the sensory analysis of gas chromatographic effluents. Food Chem. 14: 273-286 (1984) https://doi.org/10.1016/0308-8146(84)90082-7
  13. Grosch W. Flavour of coffee. A review. Nahrung 42: 344-350 (1998) https://doi.org/10.1002/(SICI)1521-3803(199812)42:06<344::AID-FOOD344>3.0.CO;2-V
  14. Diebler KD, Acree TE, Lavin EH. Aroma analysis of coffee brew by gas chromatography- olfactometry. Dev. Food Sci. 40: 69-78 (1998) https://doi.org/10.1016/S0167-4501(98)80033-2
  15. Baggenstoss J, Poisson J, Kaegi R, Perren R, Escher F. Coffee roasting and aroma formation: Application of different time-temperature conditions. J. Agr. Food Chem. 56: 5836-5846 (2008 https://doi.org/10.1021/jf800327j
  16. Mayer F, Czerny M, Grosch W. Influence of provenance and roast degree on the composition of potent odorants in arabica coffees. Eur. Food Res. Technol. 209: 242-250 (1999) https://doi.org/10.1007/s002170050487
  17. Franca AS, Oliveira LS, Oliveira RCS, Agresiti PCM, Augusti R, Mendonca JCF, Silva XA. A preliminary evaluation of the effect of processing temperature on coffee roasting degree assessment. J Food. Eng. 92: 345-352 (2009) https://doi.org/10.1016/j.jfoodeng.2008.12.012
  18. Pamela DC, Agresti M, Franca AS, Oliviera LS, Augusti R. Discrimination between defective and non-defective Brazillian coffee beans by their volatile profile. Food Chem. 106: 787-796 (2008) https://doi.org/10.1016/j.foodchem.2007.06.019
  19. Cantergiani E, Brevard H, Krebs Y, Feria-Morales A, Amado R, Yeretzian C. Characterisation of the aroma of green Mexican coffee and identification of mouldy/earthy defect. Eur. Food Res. Technol. 212: 648-657 (2001) https://doi.org/10.1007/s002170100305
  20. Toci AT, Farah A. Volatile compounds as potential defective coffee beans' markers. Food Chem. 108: 1133-1141 (2008) https://doi.org/10.1016/j.foodchem.2007.11.064
  21. Hashim L, Chaveron H. Use of methylpyrazine ratios to monito the coffee roasting. Food Res. Int. 28: 619-623 (1996)
  22. Maeztu L, Sanz C, Andueza S, MP De Pena, Belllo J, Cid C. Characterization of Espresso coffee aroma by static headspace GC-MS and sensory flavor profile. J. Agr. Food Chem. 49: 5437- 5444 (2001) https://doi.org/10.1021/jf0107959
  23. Guth H, Grosch W. Identification of the character impact odorants of stewed beef juice by instrumental analyses and sensory studies. J. Agr. Food Chem. 42: 2862-2866 (1994) https://doi.org/10.1021/jf00048a039
  24. Kim KO, Lee YC. The Sensory Evaluation of Food. Hakyonsa, Seoul, Korea. pp.116-124, pp. 236-237 (1995)
  25. Lingle TR. The coffee cupper's handbook; Appendix. Specialty Coffee Association of America. http://scaa.org/ Accessed date Feb. 9, 2011.
  26. Staub C, Lingle T. The Agtron/SCAA Roast Color Classification System Specialty Coffee Association of America http://scaa.org/ Accessed date Feb. 9, 2011.
  27. Nebesny E, Budryn G. Evaluation of sensory attributes of coffee brews from robusta coffee roasted under different conditions Eur. Food Res. Technol. 224: 159-165 (2006) https://doi.org/10.1007/s00217-006-0308-y
  28. Nebesny E, Budryn G, Kula J, Majda T. The effect of roasting method on headspace composition of robusta coffee bean aroma Eur. Food Res. Technol. 225: 9-19 (2007) https://doi.org/10.1007/s00217-006-0375-0
  29. Schenker S, Heinemann C, Huber M, Pompizzi R, Perren R, Escher F. Impact of roasting conditions on the formation of aroma compounds in coffee beans. J. Food Sci. 67: 60-66 (2002) https://doi.org/10.1111/j.1365-2621.2002.tb11359.x
  30. Gretsch C, Sarrazin C, Liadon R. Evolution of coffee aroma characteristics during roasting. pp. 27-34. In: 18th International Conference on Coffee Science, Helsinki, Finland, Association Scientific International du Cafe, Paris, France (1999)
  31. Kranz P, Braun N, Schulze N, Kunz B. Sensory quality of functional beverages: Bitterness perception and bitter masking of olive leaf extract fortified fruit somoothies. J. Food Sci. 75: S308-S311 (2010) https://doi.org/10.1111/j.1750-3841.2010.01698.x
  32. Mondello L, Costa R, Tranchida PQ, Dugo P, Presti ML, Festa S, Fazio A, Dugo G. Reliable characterization of coffee bean aroma profiles by automated headspace solid phase microextraction-gas chromatography-mass spectrometry with the support of dual-filter mass spectra library. J. Sep. Sci. 28: 1101-1109 (2005) https://doi.org/10.1002/jssc.200500026
  33. Lopez-Galilea I, Fournier N, Cid C, Guichard E. Changes in headspace volatile concentration of coffee brews caused by the roasting process and the brewing procedure. J. Agr. Food Chem. 54: 8560-8566 (2006) https://doi.org/10.1021/jf061178t
  34. Merrit C, Robertson DH, McAdoo DJ. The relationship of volatile compounds in roasted coffee beans to their precursors. pp. 144-148. In: 4th International Scientific Colloquium on Coffee, Amsterdam. ASIC, Paris, France (1970)
  35. Baltes W. The importance of the Maillard reaction in the formation of aroma in food. Lebensm. Gerichtl. Chem. 34: 39-47 (1980)
  36. Fiddler W, Parker WE, Wasserman AE, Doerr RC. Thermal decomposition of ferulic acid. J. Agr. Food Chem. 15: 757-761 (1967) https://doi.org/10.1021/jf60153a003
  37. Blank I, Sen A, Grosch W. Potent odorants of the roasted powder and brew of arabica coffee. Z. Lebensm. Unters. For. 195: 239- 245 (1992) https://doi.org/10.1007/BF01202802
  38. Semmelroch P, Laskawy G, Blank I, Grosch W. Determination of potent odourants in roasted coffee by stable isotope dilition assays. Flavour Frag. J. 10: 1-7 (1995) https://doi.org/10.1002/ffj.2730100102

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