Effects of Gliadin Fractions on Functional Properties of Wheat Dough Depending on Molecular Size and Hydrophobicity

Abstract

The effects of α‐ + β‐, γ‐, ω‐ and total gliadins on mixing, extension baking, and techno‐functional properties of doughs from hard and soft flours were measured using small‐scale techniques. The addition of all gliadin fractions resulted in decreased mixing time, peak resistance, maximum resistance to extension, and loaf height, and in increased resistance breakdown and extensibility. The various gliadin fractions showed differences in functional properties, with γ‐gliadin reducing the mixing time and maximum resistance to extension to the greatest extent, ω‐gliadin contributing to the greatest reduction in loaf height, and α‐ + β‐gliadins having the least effect on reducing loaf height. The effects of gliadin fractions on loaf height were correlated with molecular mass, and effects on mixing time, maximum resistance to extension, and extensibility were correlated with hydrophobicity.

Quantification of monomeric and polymeric wheat proteins and the relationship of protein fractions to wheat quality

“…28,41 Some of the differences observed in dough properties between cultivars may be due to differences in LMW-GS and gliadin composition. 7,31 However, these alone do not account for variability in dough properties. Recent reports 42,43 indicate that the glutenin-to-gliadin ratio also plays a role in determining dough properties.…”

“…Wheat protein quality depends on the presence or absence of specific high-molecular-weight glutenin subunits (HMW-GS), 4 low-molecular-weight glutenin subunits (LMW-GS) 5 and gliadins. 6,7 It also depends on the ratio of monomeric to polymeric proteins 8,9 and the molecular size distribution of glutenin. 10 The importance of accurate assessment of protein composition as a tool in understanding the biochemical basis of wheat quality has long been recognised.…”

Effect of Allelic Variation in Triticin on Bread- and Chapati-Making Qualities of Wheat (Triticum aestivum)

“…10) makes a significantly larger contribution to dough properties than those encoded by Glu-B1 (17 ? 18), while subunit 1 encoded by Glu-A1 made the smallest contribution to functionality [39]. Sontag-Strohm et al found that progeny carrying allele Glu-A1b (subunit 2*) had significantly greater SDS sedimentation-volumes than the null allele Glu-A1c, and that adding a HMW glutenin subunit affected extensiograph dough strength more than adding a LMW glutenin subunit, although both increased the SDSsedimentation volumes [37].…”

Genomics of consumer traits in chapatti quality

“…Fido et al (1997) isolated and purified individual groups of gliadins (α-, beta-, γ-, ω-1 and ω-2) and observed all to be reducing the dough strength on addition to flour. Uthayakumaran et al, (2001) also observed that the added gliadin fractions decreased the mixing time, peak resistance, maximum resistance to extension, and loaf height, and increased resistance breakdown and extensibility. The rheological tests are the most commonly used test to determine the quality of the flour.…”

“…In chapatti, gliadins are found to increase the extensibility of dough (Paterson and Piggott, 2006). Khatkar et al, (2002) found gliadins to positively affect the bread loaf volume, while Uthayakumaran et al, (2001) found contradictory results. Prabhasankar (2002) proposed that chapatti making quality is relative to lower levels of gliadin content, whereas (Ram and Nigam, 1982) proposed quantity of glutenin, gliadins and residual proteins as responsible for good chapatti quality.…”