Cereal Chem 63:365-369   |  VIEW ARTICLE
Molecular Comparison of Alcohol-Soluble Wheat and Buckwheat Proteins.

J. H. Skerritt. Copyright 1986 by the American Association of Cereal Chemists, Inc. 

The classification of buckwheat (Fagopyrum esculentum Moench) with the cereals in commerce and descriptions of glutenlike proteins in buckwheat endosperm have confused public understanding of the suitability or otherwise of buckwheat for gluten-free diets. Comparisons of buckwheat and wheat proteins according to amino acid composition, electrophoresis, and immunological reaction revealed little or no similarities. Whereas most of the material extracted from wheat flour by 70% ethanol (following salt extraction) was protein in nature, similar extracts from buckwheat contained only 2.4% nitrogen. Unlike wheat gliadin, the corresponding buckwheat fraction was rich in lysine, arginine, and glycine; it was not electrophoretically resolvable into gliadinlike bands on lactate-buffered polyacrylamide gels, and on sodium dodecyl sulfate polyacrylamide gels, it had only minor components in the gliadin molecular size range. Immunological studies with rabbit polyclonal and mouse monoclonal antibodies shoed little cross-reactivity between cereal prolamins and buckwheat proteins. Celiac sera with high IgG anti-gliadin titers also reacted very weakly with buckwheat proteins. These results suggest that alcohol-soluble buckwheat proteins (which are only minor components of the endosperm) bear little molecular similarity to wheat prolamins; descriptions of the former as glutenlike are misleading.