Water Diffusivity in Starch-Based Systems

  • R. B. Leslie
  • P. J. Carillo
  • T. Y. Chung
  • S. G. Gilbert
  • K. Hayakawa
  • S. Marousis
  • G. D. Saravacos
  • M. Solberg
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 302)


The objective of this study was to investigate the influence of structure, and component interactions, on the sorption and transport properties of water in starch-based systems. We compared the effective diffusivity (Deff) of water in two starches, with differing amylose-amylopectin ratios, using either kinetics of water adsorption or analysis of drying curves (water desorption) to estimate Deff. The effect of incorporating small sugar molecules into the granular or gelatinized starch matrices on Deff was measured by drying curve analysis. To investigate the possible mechanisms of water transport, the porosity and microscopic appearance of the samples at different stages of drying were determined.

In a complementary study, sorption isotherms and the number of accessible “binding” sites in the starch and starch-sugar systems were determined using gravimetric analysis and inverse gas chromatography (IGC) ‘probe analysis’. In the case of the starch-sugar systems, the measurements were made after the components had been ‘mechanically mixed’, or after more intimate mixing had been achieved by a co-freeze-drying process.

The Deff of the starches was found to depend, in a complex way, on the moisture content of the samples. At relatively high moisture contents, the predominant mode of water transport was by liquid diffusion. As the samples became drier, their porosity increased, and the predominant mode of moisture transport was by vapor phase diffusion. As the samples became very dry (less than 10% water content), Deff fell significantly. Incorporation of sugars, in general, led to a reduction of Deff, which was correlated with a corresponding fall in porosity.

In agreement with the findings of other workers, for the starches studied, the value of Deff determined from water adsorption measurements was significantly less than Deff determined from water desorption (drying curve analysis). The form of the Deff versus moisture content relationship was, however, independent of the method of measurement (adsorption or desorption). The water sorption and IGC probe analysis results indicated that some physico-chemical interaction was expedited by the freeze-drying process. This interaction was manifested by a reduction in water sorption at a given relative vapor pressure, and by major changes in the accessibility of the co-freeze-dried samples to organic probe molecules.

Taken together, the results indicate that water transport (diffusion) in starches and in starch-sugar mixtures is dependent significantly on gross structural features (development of porosity during drying), but that specific molecular, physico-chemical interactions must also be considered.


Effective Diffusivity Starch Granule Water Sorption Sugar Mixture Liquid Diffusion 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    P. Fish, Diffusion and thermodynamics of water in potato starch gels, in: “Fundamental Aspects of Dehydration of Foodstuffs,” Soc. Chem. Industry, London (1958).Google Scholar
  2. 2.
    T.P. Hanson, W.D. Cramer, W.H. Abraham, and E.B. Lancaster, Rates of water-vapor adsorption in granular corn starch, in: “Food and Bioengineering — Fundamental and Industrial Aspects,” B. Lawrence and E.J. Koval, eds., Chem. Eng. Prog. Symp. Series No. 108, Vol. 67 (1971).Google Scholar
  3. 3.
    G.D. Saravacos and G.S. Raouzeos, Diffusivity of moisture during air drying of starch gels, in: “Engineering and Food,” B.M. McKenna, ed., Elsevier Applied Science, London (1984).Google Scholar
  4. 4.
    G. Villalobos, Non-linear transient state moisture sorption of dehydrated food, Ph.D. Thesis, Rutgers University, New Brunswick, NJ (1986).Google Scholar
  5. 5.
    B. Biquet and T.P. Labuza, New model gel system for studying water activity of foods, J. Food Proc. Pres. 12:151 (1988).CrossRefGoogle Scholar
  6. 6.
    B. Biquet, Moisture transfer in foods and edible barriers, M.S. Thesis, University of Minnesota, St. Paul, MN (1987).Google Scholar
  7. 7.
    Y.C. Hong, A.S. Bakshi, and T.P. Labuza, Finite element modelling of moisture transfer during storage of mixed multi-component dried foods, J. Food Sci. 51:554 (1986).CrossRefGoogle Scholar
  8. 8.
    J. Chirife, Fundamentals of the drying mechanism during air dehydration of foods, in: “Advances in Drying,” Vol. 1, A. Mujumdar, ed., Hemisphere, New York (1983).Google Scholar
  9. 9.
    S.N. Marousis, V.T. Karathanos, and G.D. Saravacos, Effect of sugars on the water diffusivity in hydrated granular starches, J. Food Sci. 54:1496 (1989).CrossRefGoogle Scholar
  10. 10.
    A.C. Jason and G.R. Peters, Analysis of bimodal diffusion of water in fish muscle, J. Phys. D:Appl. Phys. 6:512 (1973).CrossRefGoogle Scholar
  11. 11.
    K.I. Hayakawa, Predicting an equilibrium state value from transient state data, J. Food Sci. 39:272 (1974).CrossRefGoogle Scholar
  12. 12.
    J. Crank, “The Mathematics of Diffusion,” 2nd edn., Oxford University Press, Oxford (1975).Google Scholar
  13. 13.
    G.D. Saravacos, Mass transfer properties of foods, in: “Engineering Properties of Foods,” M.A. Rao and S.S. Rizvi, eds., Marcel Dekker, New York (1986).Google Scholar
  14. 14.
    S. Bruin and K. Luyben, Drying of food materials. A review of recent developments, in: “Advances in Drying,” A. Mujumdar, ed., Vol. 1, Hemisphere, New York (1983).Google Scholar
  15. 15.
    R.H. Perry and D.W. Green, “Perry’s Chemical Engineers Handbook,” 6th edn., McGraw Hill, New York (1984).Google Scholar
  16. 16.
    G.D. Saravacos and S. Marousis, personal communication (1988).Google Scholar
  17. 17.
    G.D. Smith, “Numerical Solution of Partial Differential Equations: Finite Difference Methods,” Oxford University Press, Oxford (1978).Google Scholar
  18. 18.
    K.M. Brown and J.E. Dennis, Derivative free analogues of the Levenberg-Marquardt and Gauss algorithms for nonlinear least squares approximation, Numerische Mathematik. 18:284 (1972).Google Scholar
  19. 19.
    C.M. Metzler, G.L. Elgring, and A.J. McEwen, “A user’s manual for nonlinear and associated programs. Research Biostatistics,” The Upjohn Co., Kalamazoo, MI (1976).Google Scholar
  20. 20.
    L. Greenspan, Humidity fixed points of binary saturated aqueous solutions, J. Res. NBS.A. Physics & Chem. 81A:89 (1977).CrossRefGoogle Scholar
  21. 21.
    R.H. Stokes and R.A. Robinson, Standard solutions for humidity control at 25°C, Ind. Eng. Chem. 41:2013 (1949).CrossRefGoogle Scholar
  22. 22.
    P.J. Carillo, S.G. Gilbert, and H. Daun, Starch/solute interaction in water sorption as affected by pretreatment, J. Food Sci. 53:1199 (1988).CrossRefGoogle Scholar
  23. 23.
    K.I. Hayakawa and P.S.M. Huang, Apparent thermophysical constants for thermal and mass exchanges of cookies undergoing commercial baking processes, Lebens.-Wissensch U.-Technol. 14:336 (1981).Google Scholar
  24. 24.
    H. Levine and L. Slade, A polymer physico-chemical approach to the study of commercial starch hydrolysis products (SHP’s), Carbohydr. Polym. 6:213 (1986).CrossRefGoogle Scholar
  25. 25.
    R. Toei, Drying mechanisms of capillary porous bodies, in: “Advances in Drying,” A. Mujumdar, ed., Vol. 1, Hemisphere, New York (1983).Google Scholar
  26. 26.
    A. Brown and D. French, Specific adsorption of starch oligosaccharide in the gel phase of starch granules, Carbohydr. Res. 59:203 (1977).CrossRefGoogle Scholar
  27. 27.
    P. Chinachoti and M.P. Steinberg, Interaction of sucrose with starch during dehydration as shown by water sorption, J. Food Sci. 49:1604 (1984).CrossRefGoogle Scholar
  28. 28.
    P. Chinachoti and M.P. Steinberg, Crystallinity of waxy-maize starch as influenced by ambient temperature, absorption and desorption, sucrose content and water activity, J. Food Sci. 51:997 (1986).CrossRefGoogle Scholar
  29. 29.
    S.J. Richardson, I.C. Baianu, and M.P. Steinberg, Mobility of water in starch powders by nuclear magnetic resonance, Starch 39:198 (1987).CrossRefGoogle Scholar
  30. 30.
    A. Suggett, Polysaccharides, in: “Water — A Comprehensive Treatise,” F. Franks, ed., Plenum Press, New York (1975).Google Scholar

Copyright information

© Springer Science+Business Media New York 1991

Authors and Affiliations

  • R. B. Leslie
    • 1
  • P. J. Carillo
    • 1
  • T. Y. Chung
    • 1
  • S. G. Gilbert
    • 1
  • K. Hayakawa
    • 1
  • S. Marousis
    • 1
  • G. D. Saravacos
    • 1
  • M. Solberg
    • 1
  1. 1.Center for Advanced Food Technology and Department of Food Science, Cook College/New Jersey Agricultural Experiment Station, RutgersThe State University of New JerseyCook College, New BrunswickUSA

Personalised recommendations