Cereal Chem 72:545-551 |
Quantification of Glutenin Subunits by Sequential Acetone Precipitation and by Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE) Coupled with Densitometry Using a Known Quantity of Glutenins as a Standard.
G. Hou and P. K. W. Ng. Copyright 1995 by the American Association of Cereal Chemists, Inc.
Glutenin subunit groups (high molecular weight glutenin subunits, [HMW-GS]; low molecular weight glutenin subunits [LMW-GS]) were quantified by a sequential acetone precipitation method and by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) coupled with densitometry using a known quantity of extractable glutenin proteins as a quantitative standard. The average quantity of extractable HMW-GS analyzed in 17 soft wheat patent flours was 8.46 and 7.26% of flour protein by the sequential acetone precipitation and densitometric methods, respectively, whereas the average quantity of extractable LMW- GS was 15.29% of flour protein by the sequential acetone precipitation method and 17.07% of flour protein by the densitometric method. The mean total quantities of extractable glutenin subunits in the 17 flour samples determined by these two methods were 23.75 and 24.33%, respectively. There were no significant differences between the two methods (P greater than 0.05) in the quantities of the total glutenins determined. However, the quantities of HMW-GS, LMW-GS, and total glutenin subunits determined by each of the procedures were highly correlated. The densitometric quantification of glutenin subunit groups with the aid of a known quantity of glutenin proteins as a quantitative standard was shown to be an effective method because of its speed, small sample size, reliability, and simultaneous quantification and characterization of glutenin subunits.