Sequential Extraction and Quantitative Recovery of Gliadins, Glutenins, and Other Proteins from Small Samples of Wheat Flour

Abstract

Methods to sequentially extract and fractionate wheat flour proteins were evaluated to reliably quantify gliadins, glutenins, and albumins/globulins in single flour samples. Compositions of the resulting protein fractions were analyzed by RP-HPLC combined with SDS-PAGE. Unknown proteins were identified by mass spectrometry or N-terminal sequencing. The best separation and recovery of discrete albumin/globulin, gliadin, and glutenin fractions from the same flour sample was achieved by extraction with 0.3 M NaI in 7.5% 1-propanol followed by 2% SDS, 25 mM DTT in 25 mM TRIS, pH 8.0, and precipitation of the solubilized proteins with ammonium acetate/methanol followed by acetone. Average flour composition for the variety Butte86 was 10% albumin/globulin, 40% gliadin, and 48% glutenin. This method should be useful for determining flour composition in diverse samples and evaluating relationships between proteins and end-use functionality.

Mass spectrometry analysis of gliadins in celiac disease

“…Other procedures of extraction are mainly variations of the Osborne procedure where the composition of the buffer is slightly modified, 21 or combine different steps of extraction and precipitation to sequentially extract and fractionate wheat flour proteins in order to reliably quantify gliadins, glutenins, and albumins/globulins in flour samples. 22 Current methods of gliadin classification rely on analysis by electrophoresis or by reversed-phase high-performance liquid chromatography (RP-HPLC). 20 With both the methods, the gliadin subfractions can be differentiated allowing, for instance, to distinguish wheat varieties.…”

Mineral composition of wheat flour consumed in Brazilian cities

“…For this reason, several papers have been written on the characterization and nutritional evaluation of this cereal and its flour. [1][2][3][4][5][6][7][8][9][10] Prabhasankar and Rao evaluated the lipid content and fatty acid composition in wheat flours. 1 Yu and co-workers compared the antioxidant…”

“…4 A recent paper determined the effects of genotype and growing environment on the phenolic contents and antioxidant activities of alcohol-soluble extracts from commercial wheat cultivars. 5 Dupont et al 6 proposed a method of sequential extraction for determination of gliadins, glutenins and other proteins in wheat flour. The phytochemical compositions and antioxidant activities of bran samples of seven wheat varieties from four different countries were evaluated.…”

The Effect of Maillard Conjugation of Deamidated Wheat Proteins with Low Molecular Weight Carbohydrates on the Secondary Structure of the Protein

“…In this region of the gel, the bands for the non-incubated and incubated sIWP alone corresponded to molecular weights of 11.5 kDa, and 11.6 kDa, respectively. This band is possibly the 0.19 dimeric alpha-amylase inhibitor (AAV39519) of the LMWalbumins, which has approximately six lysine residues and one N-terminal amino group 38 .…”