A fibrous model for gellan gels from atomic force microscopy studies

  • V. J. MorrisEmail author
  • A. R. Kirby
  • A. P. Gunning
Conference paper
Part of the Progress in Colloid and Polymer Science book series (PROGCOLLOID, volume 114)


Atomic force microscopy has been used to investigate the mechanism of gelation and the nature of the long-range molecular structure in gellan gum gels. Gellan gum has been studied as a model for thermoreversible polysaccharide gels. Images have been obtained of aggregates, gel precursors, aqueous films and bulk 3D aqueous gels. In the absence of gel-promoting cations helix formation leads to the formation of elongated partly branched filaments. These filaments are of constant height and width, and association appears to involve just helix formation, without side-by-side aggregation of the helices. In the presence of the gel-promoting cation potassium gel precursors consisting of branched fibres of variable height and width are formed. These are believed to arise from side-by-side aggregation of the helical filaments. Similar branched fibrous structures have been observed forming the network structures of aqueous gellan films or 3D gels. The gel structure is seen to be a continuous branched network. There are no discrete junction zones: rather cation binding and helix association is continuous throughout the network.

Key words

Atomic force microscopy Gellan Gels Gelation 


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  1. 1.
    O’Neil MA, Selvendran RR, Morris VJ (1983) Carbohydr Res 124: 123CrossRefGoogle Scholar
  2. 2.
    Jansson P-E, Lindberg B Sandford PA (1983) Carbohydr Res 124: 135CrossRefGoogle Scholar
  3. 3.
    Kuo MS, Mort AJ, Dell A (1986) Carbohydr Res 156: 173CrossRefGoogle Scholar
  4. 4.
    Sandford PA, Cottrell IW, Pettit DJ (1984) Pure Appl Chem 56: 879CrossRefGoogle Scholar
  5. 5.
    Baird JK, Sandford PA, Cottrell IW (1983) Biol Technol 1: 778Google Scholar
  6. 6.
    Morris VJ (1996) In: Stephen AM (ed) Food polysaccharides and their applications. Dekker, New York, p 341Google Scholar
  7. 7.
    Robinson G, Manning CE, Morris ER In: Dickinson E (ed) Food polymers, gels and colloids. Royal Society Chemistry, London, p 22Google Scholar
  8. 8.
    Yugichi Y, Mimura M, Kitamura S, Urakawra H, Kajiwara (1993) Food Hydrocolloids 7: 373CrossRefGoogle Scholar
  9. 9.
    Yoshide H, Takahashi M (1993) Food Hydrocolloids 7: 387CrossRefGoogle Scholar
  10. 10.
    Carroll V, Miles MJ, Morris VJ (1982) Int J Biol Macromol 4: 432CrossRefGoogle Scholar
  11. 11.
    Attwool PT, Atkins EDT, Upstill C, Miles MJ, Morris VJ (1986) In: Wedlock DJ, Williams PA, Phillips GO (eds) Gums and stabilisers for the food industry, vol 3. IRL, Oxford, p 135Google Scholar
  12. 12.
    Chandrasekaran R, Millane RP, Arnott S (1988) In: Phillips GO, Wedlock DJ, Williams PA (eds) Gums and stabilisers for the food industry 4. IRL Oxford, p 183Google Scholar
  13. 13.
    Chandrasekaran R, Puigianer LC, Joyce KL, Arnott S (1988) Carbohydr Res 181:23CrossRefGoogle Scholar
  14. 14.
    Chandrasekaran R, Millane RP, Arnott S, Atkins EDT (1988) Carbohydr Res 175: 1CrossRefGoogle Scholar
  15. 15.
    Chandrasekaran R, Radha A, Thailambal VG (1992) Carbohydr Res 224:1CrossRefGoogle Scholar
  16. 16.
    Chandrasekaran R, Thailambal VG (1990) Carbohydr Res 12: 431CrossRefGoogle Scholar
  17. 17.
    Gunning AP, Morris VJ (1990) Int J Biol Macromol 12: 338CrossRefGoogle Scholar
  18. 18.(a)
    Gunning AP, Kirby AR, Ridout MJ, Brownsey GJ, Morris VJ (1996) Macromolecules 29: 6791CrossRefGoogle Scholar
  19. 18.(b)
    Gunning AP, Kirby AR, Ridout MJ, Brownsey GJ, Morris VJ (1997) Macromolecules 30: 163CrossRefGoogle Scholar
  20. 19.
    Wong TMH (1991) PhD thesis. University of Cambridge, UKGoogle Scholar
  21. 20.
    Rees DA, Morris ER, Thom D, Madden J (1982) In: Aspinall GO (ed) The polysaccharides, vol 1. Academic Press, New York, p 195Google Scholar
  22. 21.
    Gunning AP, Kirby AR, Morris VJ, Wells B, Brooker BE (1995) Polym Bull 34: 615CrossRefGoogle Scholar
  23. 22.
    Kirby AR, Gunning AP, Morris VJ (1996) Biopolymers 38: 355CrossRefGoogle Scholar
  24. 23.
    Radmacher M, Fritz M, Hansma PK (1995) Biophys J 69: 264CrossRefGoogle Scholar
  25. 24.
    Suzuki A, Yamazaki M, Kobiki Y (1996) J Chem Phys 104: 1751CrossRefGoogle Scholar
  26. 25.
    Wigren R, Billsten P, Erlandsson R, Lofas S, Lundstrom I (1995) J Colloid Interface Sci 9: 1594Google Scholar
  27. 26.
    Haugstad G, Gladfelter WL, Keyes MP, Weberg EB (1993) Langmuir 9: 1594CrossRefGoogle Scholar
  28. 27.
    Burne PM, Sellon DB (1994) Biopolymers 34: 371CrossRefGoogle Scholar
  29. 28.
    Yuguchi Y, Mimura M, Urakawa H, Kitamura S, Ohnot S, Kajiwara (1996) Carbohydr Polym 30: 83CrossRefGoogle Scholar
  30. 29.
    Izumi Y, Kituta N, Sakai K, Takezawa H (1996) Carbohydr Polym 30: 121CrossRefGoogle Scholar
  31. 30.
    Stokke Elgaester A, Kitamura S (1993) Int J Biol Macromol 15: 63CrossRefGoogle Scholar
  32. 31.
    McIntire TM, Brant DA (1997) Biopolymers 42: 133CrossRefGoogle Scholar
  33. 32.
    Nakajima K, Ikehara T, Nishi T (1996) Carbohydr Polym 30: 77CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 1999

Authors and Affiliations

  1. 1.Institute of Food ResearchColneyUK

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