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vol. 7, nr. 1 (2006)
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Water vapour transmission properties of wheat starch-sorbitol film
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Danuta M. Napierała, Alina Nowotarska
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Department of Physics, University of Agriculture, ul. Wojska Polskiego 38/42, 60-637 Poznań |
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vol. 7 (2006), nr. 1,
pp. 151-159
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abstract:
The barrier properties of wheat starch-sorbitol cast film with respect to water vapour at three water activity gradients: 0.33, 0.54, 0.94 and temperature range 297- 309 K have been determined. The water vapour permeability was found to be influenced by the water behaviour obeying the Fickian law. Temperature dependence of the permeability coefficient, obtained from the steady-state permeation flux and revealing Arrhenius-type relationships, permitted a calculation of the mean activation energy of water vapour transport through the film. High value of the activation energy for the permeation process at the water activity gradient of 0.54, in comparison to other water activities gradients studied, suggests that in these conditions hydrophilic starch-sorbitol film can be an effective barrier for water vapour.
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keywords:
starch film, water vapour transmission, permeation coefficient, diffusion, sorbitol
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original in:
Polish
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