Influence of processing on the content of sugars in green Arabica coffee beans

Original Paper


Quantitative analyses of low molecular sugars in green coffees (Coffea arabica L. var. Acaià) that were processed in parallel either by the traditional wet or the traditional dry method, revealed a close correlation between the kind of post-harvest treatment and the contents of fructose and glucose. While in washed coffee beans (wet processing) only low amounts of these both hexoses were present, those in unwashed coffees (dry processing) were significantly higher. Model-processing experiments in the laboratory confirmed these findings. Moreover, a comparison with the untreated controls revealed that the low levels of both sugars are the consequence of a decrease in the case of wet processing, whereas they remained unchanged or even increased in the case of dry processing. Further minor sugars are also affected by post-harvest treatment. The amounts of galactose, arabinose and mannose show a similar arrangement as those for glucose and fructose, although their overall concentration is about 100-fold lower. Sucrose, the major low molecular sugar in green coffee beans, is not significantly affected by coffee processing. The influence of an active seed metabolism on the observed alterations of the sugar concentrations is discussed.


Coffea arabica Glucose Fructose Sucrose Green coffee Post-harvest treatment Coffee processing 


  1. 1.
    Streuli H (1974) Der heutige Stand der Kaffeechemie. In: Proceedings of the “6ème Colloque International sur la Chimie des Cafés Verts” ASIC Paris, pp 61–72Google Scholar
  2. 2.
    Illy A, Viani R (1995) Espresso coffee: the chemistry of quality. Academic Press, London San DiegoGoogle Scholar
  3. 3.
    Maier HG (1981) Kaffee. Paul Parey Verlag, Berlin HamburgGoogle Scholar
  4. 4.
    Sivetz M, Desrosier NW (1979) In: Sivetz M, Desrosier NW (eds) Coffee technology. Avi Publishing, Westport, CN, pp 74–116Google Scholar
  5. 5.
    Selmar D, Bytof G, Knopp SE (2002) New aspects of coffee processing: the relation between seed germination and coffee quality. In: Proceedings of the “19eme Colloque Scientifique International sur le Café”: ASIC ParisGoogle Scholar
  6. 6.
    Bytof G, Knopp SE, Schieberle P, Teutsch I, Selmar D (2005) Eur Food Res Technol 220:245–250Google Scholar
  7. 7.
    Homma S (2001) In: Clarke RJ, Vitzthum OG (eds) Coffee—recent developments. Blackwell, Oxford, pp 50–67Google Scholar
  8. 8.
    Wootton AE (1974) The dry matter loss from parchment coffee during field processing. In: Proceedings of the “16eme Colloque International sur la Chimie des Cafés Verts” ASIC Paris, pp 316–324.Google Scholar
  9. 9.
    Selmar D, Bytof G, Knopp SE, Bradbury A, Wilkens J, Becker R (2005) Biochemical insights into coffee processing: Quality and nature of green coffees are interconnected with an active seed metabolism. In: Proceedings of the 20ème Colloque Scientifique International sur le Café”: ASIC, ParisGoogle Scholar
  10. 10.
    Selmar D, Hunecke D, Junghärtchen I, Breitenstein B, Bytof G, Knopp SE (2005) Expression of isocitrate lyase and the abundance of ß-tubulin: feasible markers for the estimation of germination processes in differently processed green coffees In: Proceedings of the 20ème Colloque Scientifique International sur le Café”: ASIC, ParisGoogle Scholar
  11. 11.
    Lüllmann C, Silwar R (1989) Lebensmittel Gericht Chem 43:42–43Google Scholar
  12. 12.
    Tressl R, Wondrak GT, Garbe LA, Rewicki D, Krüger RP (1998) J Agric Food Chem 46:1765–1776Google Scholar
  13. 13.
    Bradbury AGW (2001) In: Clarke RJ, Vitzthum OG (eds) Coffee. Recent developments. Blackwell, Oxford, pp 1–17Google Scholar
  14. 14.
    Silwar R, Lüllmann C (1988) Café Cacao Thé 32:319–322Google Scholar
  15. 15.
    Guyot B, Guelle D, Assemat S, Tchana E, Pomathios L (1995) Influence du mode de préparation du café vert robusta sur sa composition chimique et ses qualités organoleptiques. In: Proceedings of the “16eme Colloque Scientifique International sur le Café”. ASIC Paris, pp 267–277Google Scholar
  16. 16.
    Bucheli P, Meyer I, Pasquier M, Locher R (1996) Plant Physiology Biochem Special Issue: 10th FESPP Congress Florence Italy, L-12 pp 325Google Scholar
  17. 17.
    Bewley JD, Black M (1994) Seeds. Physiology of development and germination. Plenum, New York LondonGoogle Scholar
  18. 18.
    Menchú JF, Rolz C (1973) Café Cacao Thé 17:53–61Google Scholar
  19. 19.
    Roberts JKM, Callis J, Wemmer D, Walbot V, Jaretzky O (1984) Proc Nat Acad Sci USA 81:3379–3383PubMedADSGoogle Scholar
  20. 20.
    Menegus F, Cattaruzza L, Chersi A, Fronza G (1989) Plant Physiol 90:29–32CrossRefPubMedGoogle Scholar
  21. 21.
    Summers JE, Ratcliffe RG, Jackson MB (2000) J Exp Bot 51:1413–1422PubMedGoogle Scholar
  22. 22.
    Stenlid G (1954) Physiol Plant 7:173–181Google Scholar
  23. 23.
    Stein JC, Hansen G (1999) Plant Physiology 121:71–79PubMedGoogle Scholar
  24. 24.
    Mazzafera P (1999) Chemical composition of defective coffee beans. Food Chem 64:547–554Google Scholar
  25. 25.
    Avelino J, Barboza B, Araya JC, Fonseca C, Davrieux F, Guyot B, Cilas C (2005) J Sci Food Agric 8: 1869-1876Google Scholar

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  1. 1.Institute of Plant BiologyTechnical University BraunschweigBraunschweigGermany

Personalised recommendations