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Wheat gluten amino acid composition analysis by high-performance anion-exchange chromatography with integrated pulsed amperometric detection
A simple accurate method for determining amino acid composition of wheat gluten proteins and their gliadin and glutenin fractions using high-performance anion-exchange chromatography with integrated pulsed amperometric detection is described. In contrast to most conventional methods, the analysis re...
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Published in: | Journal of Chromatography A 2009-07, Vol.1216 (29), p.5557-5562 |
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Main Authors: | , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | A simple accurate method for determining amino acid composition of wheat gluten proteins and their gliadin and glutenin fractions using high-performance anion-exchange chromatography with integrated pulsed amperometric detection is described. In contrast to most conventional methods, the analysis requires neither pre- or post-column derivatization, nor oxidation of the sample. It consists of hydrolysis (6.0
M hydrochloric acid solution at 110
°C for 24
h), evaporation of hydrolyzates (110
°C), and chromatographic separation of the liberated amino acids. Correction factors (
f) accounted for incomplete cleavage of peptide bonds involving Val (
f
=
1.07) and Ile (
f
=
1.13) after hydrolysis for 24
h and for Ser (
f
=
1.32) losses during evaporation. Gradient conditions including an extra eluent (0.1
M acetic acid solution) allowed multiple sequential sample analyses without risk of Glu contamination on the anion-exchange column. While gluten amino acid compositions by the present method were mostly comparable to those obtained by a conventional method involving oxidation, acid hydrolysis and post-column ninhydrin derivatization, the latter method underestimated Tyr, Val and Ile levels. Results for the other amino acids obtained by the different methods were linearly correlated (
r
>
0.99, slope
=
1.03). |
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ISSN: | 0021-9673 |
DOI: | 10.1016/j.chroma.2009.05.066 |