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HIGH PERFORMANCE LIQUID CHROMATOGRAPHY OF BARLEY PROTEINS: RELATIVE QUANTITIES OF HORDEIN FRACTIONS CORRELATE WITH MALT EXTRACT
Author(s) -
Janes Peter W.,
Skerritt John H.
Publication year - 1993
Publication title -
journal of the institute of brewing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.523
H-Index - 51
eISSN - 2050-0416
pISSN - 0046-9750
DOI - 10.1002/j.2050-0416.1993.tb01151.x
Subject(s) - chemistry , hordein , high performance liquid chromatography , chromatography , prolamin , size exclusion chromatography , dithiothreitol , storage protein , biochemistry , gene , enzyme
Several high performance liquid chromatography (HPLC) approaches have been used to study the relationships between amounts of particular groups of grain storage proteins (hordeins) and malt extract, using two sets of barley samples. The areas of several chromatogram peaks varied between samples in a manner that correlated with malt extract. Size‐exclusion HPLC of protein aggregates extracted by sonication gave negative correlations of the relative areas of the three largest chromatogram peaks with malt extract in a set of 39 samples of the one variety, but not in a set of samples of 8 varieties grown at 4–5 sites. Under reducing conditions, disulphide‐bonded hordeins were quantitatively extracted and the proportion of hordein in the largest peak, comprised of D‐ and B‐hordeins, correlated well with malt extract in both sets of samples. The hordeins sequentially extracted into 50% (v/v) 1‐propanol and 50% (v/v) 1‐propanol‐50 mM dithiothreitol (DTT) were also analysed by reversed‐phase HPLC, and could be resolved into several peaks of B‐, C‐ and D‐ hordeins. Relationships between the amount of certain C‐ hordeins in the propanol extract, and certain B‐ hordeins in the propanol‐DTT extract and malt extract were seen. As well as providing a better understanding of the relationship between barley grain protein composition and malting quality, these HPLC methods are useful additional methods to enable partial prediction of malt extract using un‐malted barley.