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Food and Bioprocess Technology

, Volume 1, Issue 1, pp 82–90 | Cite as

GAB Generalized Equation for Sorption Phenomena

  • Jiří BlahovecEmail author
  • Stavros Yanniotis
Article

Abstract

A generalization of the standard Guggenheim, Anderson, de Boer (GAB) equation is presented in this paper, which is based on the assumption that the parameter C of the GAB equation is not constant but rather some polynomial function of the water activity a w . Sorption data for wheat and potato starches were tested for the application of the generalized form of the GAB equation. It is shown that the standard GAB equation is adequate to describe experimental data for water activity values up to 0.90 but fails to adequately describe the experimental data when data in the range of a w 0.9–1.0 are included in the calculations. The generalized GAB form leads to successful description of the sorption data for water activity values from 0 to 1.

Keywords

Sorption isotherm GAB GAB generalized equation Food Polynomial approximation Water activity 

Notes

Acknowledgment

The paper was partly supported by the Research Intention MSM 6046070905 (Czech Republic).

References

  1. Blahovec, J. (2004). Sorption isotherms in materials of biological origin. Mathematical and physical approach. Journal of Food Engineering, 65, 489–495.CrossRefGoogle Scholar
  2. Brunauer, S. (1943). The absorption of the gases and vapors. I. Physical adsorption. Princeton: Princeton University Press.Google Scholar
  3. Karel, M. (1975). Water activity and food preservation. In M. Karel, O.R. Fennema & D. B. Lund (Eds.), Principles of food science, Part II. Physical principles of food preservation (pp. 237–263). New York: Marcel Dekker Inc.Google Scholar
  4. Schär, W., & Rüegg, M. (1985). The evaluation of GAB constants from water vapour sorption data. Lebensmittel-Wissenschaft und-Technologie, 18, 225–229.Google Scholar
  5. Schuchmann, H., Roy, I., & Peleg, M. (1990). Empirical models for moisture sorption isotherms at very high water activities. Journal of Food Science, 55(3), 759–762.CrossRefGoogle Scholar
  6. Timmermann, E. O., & Chirife, J. (1991). The physical state of water sorbed at high activities in starch in terms of the GAB sorption equation. Journal of Food Engineering, 13, 171–179.CrossRefGoogle Scholar
  7. van den Berg, C. (1981). Vapour sorption equilibria and other water–starch interactions: A physico-chemical approach. PhD thesis, Agricultural University, Wageningen, The Netherlands.Google Scholar
  8. van den Berg, C. (1984). Description of water activity of foods for engineering purposes by means of the GAB model of sorption. In B. M. McKenna (Ed.), Engineering and foods, Vol. 1 (pp. 311–321). New York: Elsevier.Google Scholar
  9. van den Berg, C., & Bruin, S. (1981). Water activity and its estimation in food systems: Theoretical aspects. In L. B. Rockland & G. F. Stewards (Eds.), Water activity. Influence on food quality (pp. 1–61). New York: Academic.Google Scholar
  10. Viollaz, P. E., & Rovedo, C. O. (1999). Equilibrium sorption isotherms and thermodynamic properties of starch and gluten. Journal of Food Engineering, 40, 287–292.CrossRefGoogle Scholar
  11. Yanniotis, S. (1994). A new method for interpolating and extrapolating water activity data. Journal of Food Engineering, 21, 81–96.CrossRefGoogle Scholar

Copyright information

© Springer Science + Business Media, LLC 2007

Authors and Affiliations

  1. 1.Department of PhysicsCzech University of AgriculturePrague 6—SuchdolCzech Republic
  2. 2.Department of Food Science and TechnologyAgricultural University of AthensAthensGreece

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