Abstract
Paste of defatted and/or mildly acid-hydrolyzed high amylose corn starch was freeze-thawed, and then the starch was isolated by vacuum drying for the analysis in crystallization and pasting properties. X-ray diffraction pattern and differential scanning calorimetric analysis showed that the crystallinity of the freeze-thawed starch was increased as the degree of hydrolysis increased. The diffraction pattern revealed B- and V-crystals with patterns with diffraction peaks at 17, 20, and 23-25° (2θ), which were developed by amylose recrystallization during the freeze-thawing. The crystal melting enthalpies, for dual endothermic transitions above 100 °C, which resulted from the melting of amylose-lipids complex and amylose double helices were raised by the treatment. The isolated and dried starch formed a paste by aqueous heating under the ambient pressure, and its paste viscogram exhibited substantially higher resistance to shear-thinning, and rapid setback upon cooling. Acid hydrolysis, however, reduced overall paste viscosity, possibly due to the increased crystallinity. Enzyme-resistant starch content in the acid hydrolyzed starch was increased by the freeze-thawing, but not by acid hydrolysis. It was slightly increased by defatting.
Original language | English |
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Pages (from-to) | 449-455 |
Number of pages | 7 |
Journal | Carbohydrate Polymers |
Volume | 54 |
Issue number | 4 |
DOIs | |
Publication status | Published - 2003 Dec 1 |
Bibliographical note
Copyright:Copyright 2008 Elsevier B.V., All rights reserved.
Keywords
- Acid hydrolysis
- Freeze-thawing
- High amylose corn starch
- Resistant starch
ASJC Scopus subject areas
- Organic Chemistry
- Polymers and Plastics
- Materials Chemistry