Starch Conversion

From German brewing and more
Revision as of 03:33, 7 January 2009 by Kaiser (Talk | contribs)

Jump to: navigation, search

Work in progress.jpg

[Shetty, 2006]:

  • gelatinization: heating in excess water, endothermic reaction, loss of crystalline order
  • irreversible w/r to the shape of the granule
  • amylopecting and amylose may form new structures when cooled down -> retrogradation
  • during heating -> swelling to up to 30x its weight. reversible process
  • retrogradation is cause for hard stale bread

[Donald, 2004]

  • irreversible order -> disorder transition called gelatinization.
  • swell, absorb water, leach amylose, loose crystallinity.
  • birefringence is lost
  • range is quite large for all granules 56-64 for wheat and potato but much smaller (1 C) for individual granules
  • substantial swelling
  • inital water absorption in the amorphous growth rings
  • swelling driven process
  • crystalline regions break open b/c of the swelling
  • if water is limited (high density or presence of sugars) swelling doesn't take place as well and a melting of the crystalline sections needs to happen
  • gelatinization temperature increases
  • Maize starch: from 70C to 78C when placed in 25% sugar solution.
  • sugar removes free water


  • gelatinization
  • active enzymes
  • emzyme temperature and pH optima
  • mash parameters affecting conversion


References

[Valclavik] Vickie A. Valclavik, Elizabeth W. Christian, Essentials of Food Science, Third Edition, Springer
[Champe] Pamela C, Champe, Richard A. Harvey, Denise R. Ferrier, Biochemistry, Lippincott's Illustrated Reviews
[Kunze, 2007] Wolfgang Kunze, Technologie Brauer und Maelzer, 9. Auflage, VLB Berlin
[Narziss, 2005] Prof. Dr. agr. Ludwig Narziss, Prof. Dr.-Ing. habil. Werner Back, Abriss der Bierbrauerei, Technische Universitaet Muenchen (Fakultaet fuer Brauwesen, Weihenstephan). WILEY-VCH Verlags GmbH Weinheim Germany, 2005
[Donald, 2004] A. M. Donald, Understanding Starch Stucture and Functionality, Chapter 5 in Starch in Food: Structure, Function and Applications By Ann-Charlotte Eliasson, CRC Press, 2004
[Shetty, 2006] Kalidas Shetty, Food Biotechnology, CRC Press, 2006