Premium
Microstructural Characterization of Plasticized Starch‐Based Films
Author(s) -
García María A,
Martino Miriam N.,
Zaritzky Noemí E.
Publication year - 2000
Publication title -
starch ‐ stärke
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.62
H-Index - 82
eISSN - 1521-379X
pISSN - 0038-9056
DOI - 10.1002/1521-379x(200006)52:4<118::aid-star118>3.0.co;2-0
Subject(s) - differential scanning calorimetry , crystallinity , plasticizer , materials science , amorphous solid , starch , scanning electron microscope , chemical engineering , sorbitol , oxygen permeability , composite material , chemistry , organic chemistry , oxygen , physics , engineering , thermodynamics
Edible films were developed using different starch sources (corn starch and amylomaize). Starch suspensions were cold gelatinized with NaOH; either glycerol or sorbitol were used as plasticizer. Films were characterized by Differential Scanning Calorimetry (DSC), X‐ray diffraction, Scanning Electron Microscopy (SEM) and gas (CO 2 and O 2 ) permeabilities. SEM observations showed that plasticizer addition was necessary for film integrity. The evaluation of film formation by DSC indicated that cold gelatinization was the main factor of thermal transitions. Film crystallinity was analyzed by DSC and X‐ray diffraction during storage. For all tested formulations, film crystallinity increased while gas permeability decreased during storage. Films containing glycerol or sorbitol showed a lower crystalline/amorphous ratio by X‐ray diffraction and DSC than unplasticized films. Amylomaize films with higher crystalline/amorphous ratio gave lower gas permeabilities than the corresponding corn starch films; films containing sorbitol showed lower permeability values than those containing glycerol.