GLUTENIN STRUCTURE

The fall in viscosity of dispersions of gluten when treated with excess of mercaptoethanol does not exhibit an initial induction period. This finding appears to rule out the idea that glutenin is highly crosslinked in a branching mode. It is compatible with a linear model in which one SS bond, not two, joins adjacent chains, or a model with low levels of branching. However, it is unnecessary to postulate branching crosslinks to explain glutenin properties in the present state of knowledge. The insoluble residue fraction of wheat flour protein is believed to be mainly linear glutenin of high molecular weight. A linear hypothesis can account for the Orth and Bushuk effect, in which baking quality is positively and negatively correlated with insoluble and soluble protein, respectively. It is suggested that gliadin may act as a plasticiser and aid to dispersion of glutenin. Copyright © 1979 John Wiley & Sons, Ltd