Gelatinisation related structural aspects of small and large wheat starch granules

Saved in:
Bibliographic Details
Title: Gelatinisation related structural aspects of small and large wheat starch granules
Authors: Vermeylen, Rudi1 rudi.vermeylen@scarlet.be, Goderis, Bart2, Reynaers, Harry2, Delcour, Jan A.1
Source: Carbohydrate Polymers. Nov2005, Vol. 62 Issue 2, p170-181. 12p.
Subjects: Gelation, Crystalline polymers, Coagulation, Colloids
Abstract: Abstract: Wheat starches from four European varieties (Charger, Estica, Skirlou and Soissons), and their small and large granule fractions were characterised on a structural level. Gelatinisation properties of starches and fractions thereof were compared. Isoamylase debranching revealed only limited differences between amylopectin chain lengths of the various starches and their fractions. Wide-angle X-ray diffraction, which showed predominant A-type crystallinity for all starches, revealed that large granules had systematically higher B-type and total crystallinity than small granules. Small-angle X-ray scattering (SAXS) indicated structural differences between amylopectins of distinct granule classes. At 42% moisture, the SAXS patterns of small granules were more intense than those of large granules, which, along with their higher gelatinisation peak temperature, suggested denser crystalline lamellae. Upon hydration from 42 to 66% moisture, small granules showed decreased lamellar repeat distances. As small granules displayed narrower helix–coil transition endotherms than large granules, shorter single stranded chains are envisaged to connect longer double helices to the amylopectin backbone in small wheat granules. [Copyright &y& Elsevier]
Copyright of Carbohydrate Polymers is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
Description
Abstract:Abstract: Wheat starches from four European varieties (Charger, Estica, Skirlou and Soissons), and their small and large granule fractions were characterised on a structural level. Gelatinisation properties of starches and fractions thereof were compared. Isoamylase debranching revealed only limited differences between amylopectin chain lengths of the various starches and their fractions. Wide-angle X-ray diffraction, which showed predominant A-type crystallinity for all starches, revealed that large granules had systematically higher B-type and total crystallinity than small granules. Small-angle X-ray scattering (SAXS) indicated structural differences between amylopectins of distinct granule classes. At 42% moisture, the SAXS patterns of small granules were more intense than those of large granules, which, along with their higher gelatinisation peak temperature, suggested denser crystalline lamellae. Upon hydration from 42 to 66% moisture, small granules showed decreased lamellar repeat distances. As small granules displayed narrower helix–coil transition endotherms than large granules, shorter single stranded chains are envisaged to connect longer double helices to the amylopectin backbone in small wheat granules. [Copyright &y& Elsevier]
ISSN:01448617
DOI:10.1016/j.carbpol.2005.07.021