Amylopectin internal molecular structure in relation to physical properties of sweetpotato starch

Abstract

Unit chain length distributions of amylopectins and their phi,beta-limit dextrins (reflecting amylopectin internal part) from 11 Chinese sweetpotato genotypes were characterized by high performance anion-exchange chromatography after debranching, and were related to the thermal and pasting properties of granular starches. The weight-based unit chain length profiles of whole amylopectin and their internal parts both had three distinguishable major groups with approximate range of DP 6-36, 37-68, and > 69 for amylopectins and DP 3-25, 26-55, and > 55 for phi,beta-limit dextrins. Among different genotypes, two different patterns of B(fp) (fingerprint B-chains, DP 3-7) were observed for phi,beta-limit dextrins, whereas A(fp) (fingerprint A-chains, DP 6-8) for whole amylopectins were consistent. Reconstruction of amylopectins from their phi,beta-limit dextrins revealed that B-chains with internal DP > 20 possessed an external chain length corresponding to the average value DP 12.8. Wide genetic variations were recorded among structural parameters, of which several concerning the amylopectin internal part were highly correlated to the thermal and pasting parameters of sweetpotato starches, and suggested that the internal part of amylopectin is critical to the physical behavior of granular starch. Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved.

Keywords

Internal unit chain distribution; Sweetpotato amylopectin structure; Chain category; Structure-properties relationship

Published in

Carbohydrate Polymers
2011, volume: 84, number: 3, pages: 907-918
Publisher: ELSEVIER SCI LTD

SLU Authors

• Bertoft, Eric

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Food Science

Publication identifier

• DOI: https://doi.org/10.1016/j.carbpol.2010.12.039

Permanent link to this page (URI)

https://res.slu.se/id/publ/58113