Cereal Chem 67:161-170 | VIEW
ARTICLE
Use of Sonication and Size-Exclusion High-Performance Liquid Chromatography in the Study of Wheat Flour Proteins. II. Relative Quantity of Glutenin as a Measure of Breadmaking Quality.
N. K. Singh, G. R. Donovan, and F. MacRitchie. Copyright 1990 by the American Association of Cereal Chemists, Inc.
Total unreduced proteins from flours of 15 wheat cultivars of diverse origin and breadmaking quality were fractionated by size-exclusion high-performance liquid chromatography (SE-HPLC) into three fractions of decreasing molecular size range, representing predominantly polymeric glutenin (including minor albumin and globulin aggregates), monomeric gliadins, and albumin/globulins, respectively. Relative quantity of glutenin (percent area of peak 1) was highly positively correlated with loaf volume, extensigraph dough resistance and extensibility, and mixograph peak development time of these flours (r = 0.72, 0.84, 0.84, and 0.84, respectively; P = 0.003-0.0001). Electrophoretic analysis of gliadins and glutenin subunits indicated that cultivars with a lower proportion of peak 1 usually have additional gliadin bands and/or a deficiency of glutenin subunits, providing a biochemical genetic basis for the SE-HPLC differences. A very strong negative correlation was found between relative quantity of albumin/globulin and flour protein content (r = - 0.92, P = 0.0001). Absolute quantity of glutenin (area of peak 1 per milligram of flour) also strongly correlated with quality attributes, particularly extensibility, farinograph dough development time, and dough breakdown (r - 0.76, 0.89, and -0.65, respectively; P = 0.009-0.0001). Based on earlier studies with purified and enriched glutenin and gliadin fractions, we conclude that the proportion of these proteins, particularly glutenin, has a direct effect on functionality. Because very little flour is required 11 mg, half an endosperm), this method should provide a rapid small-scale, early generation test for breadmaking quality in wheat breeding.