Exploring extraction/dissolution procedures for analysis of starch chain-length distributions

Wu, Alex Chi, Li, EnPeng and Gilbert, Robert G. (2014) Exploring extraction/dissolution procedures for analysis of starch chain-length distributions. Carbohydrate Polymers, 114 36-42. doi:10.1016/j.carbpol.2014.08.001

Author Wu, Alex Chi
Li, EnPeng
Gilbert, Robert G.
Title Exploring extraction/dissolution procedures for analysis of starch chain-length distributions
Journal name Carbohydrate Polymers   Check publisher's open access policy
ISSN 0144-8617
Publication date 2014-12-19
Year available 2014
Sub-type Article (original research)
DOI 10.1016/j.carbpol.2014.08.001
Open Access Status
Volume 114
Start page 36
End page 42
Total pages 7
Place of publication Kidlington, Oxford, United Kingdom
Publisher Pergamon Press
Collection year 2015
Language eng
Abstract The analysis of starch chain-length distributions (CLDs) is important for understanding starch biosythesis-structure-property relations. It is obtained by analyzing the number distribution of the linear glucan chains released by enzymatic debranching of starch α-(1→6) glycosidic bonds for subsequent characterization by techniques such as fluorophore-assisted carbohydrate electrophoresis (FACE) or size-exclusion chromatography (SEC). Current literature pretreatments for debranching prior to CLD determination involve varying protocols, which might yield artifactual results. This paper examines the two widely used starch dissolution treatments with dimethyl sulfoxide (DMSO) containing 0.5% (w/w) lithium bromide (DMSO-LiBr) at 80 °C and with aqueous alkaline (i.e. NaOH) solvents at 100 °C. Analyses by FACE with a very high range of degree of polymerization, and by SEC, of the CLD of barley starches with different structures show the following. (1) The NaOH treatment, even at a dilute concentration, causes significant degradation at higher degrees of polymerization, leading to quantitatively incorrect CLD results in longer amylopectin and in amylose chains. (2) Certain features in both amylopectin and amylose fractions of the CLD reduced to bumps or are missing with NaOH treatment. (3) Overestimation of amylose chains in starch CLD due to incomplete amylopectin dissolution with dilute NaOH concentration. These results indicate starch dissolution with DMSO-LiBr is the method of choice for minimizing artifacts. An improved pretreatment protocol is presented for starch CLD analysis by FACE and SEC.
Keyword Amylose
Chain length distribution
Dimethyl sulfoxide
Fluorophore assisted carbohydrate electrophoresis (FACE)
Size exclusion chromatography (SEC)
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Queensland Alliance for Agriculture and Food Innovation
Official 2015 Collection
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Citation counts: TR Web of Science Citation Count  Cited 13 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 14 times in Scopus Article | Citations
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