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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Effects of moisture content on structural and dielectric properties of cassava starch films

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Author(s):
Bergo, Paulo [1] ; Freitas Moraes, Isabel C. [1] ; do Amaral Sobral, Paulo J. [1]
Total Authors: 3
Affiliation:
[1] Univ Sao Paulo, Dept Food Engn, BR-13635900 Pirassununga, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: STARCH-STÄRKE; v. 64, n. 10, p. 835-839, OCT 2012.
Web of Science Citations: 8
Abstract

In this work, it was evaluated the effect of moisture content on the structural and dielectric properties of cassava starch films by means of Fourier Transform infrared spectroscopy (FTIR), impedancimetric, and gravimetric analysis. The film samples were equilibrated in hermetically sealed desiccators, containing different saturated salts in water in order to promote activity of water between 0.11 and 0.85. The position and amplitude of the peaks in the fingerprint region of the FTIR spectra were changed due to the modifications in the interactions between the polymeric chains and water molecules. These effects may be related to the formation of semi-crystalline regions in the film structure. The dielectric properties of the films were also strongly dependent on the moisture content, showing a non-linear and a linear region, which was attributed to the domain of bound and free water in the film, respectively. The gravimetric analyzes showed the typical sigmoidal behavior, attributed to the way the water interacts with the biopolymer. Finally, the flexibility of the films increased with water content increasing. (AU)