Cereal Chem. 71:75-82 | VIEW
Effects of Genotype and Nitrogen Nutrition on Protein Aggregates in Barley.
F. Benetrix, A. Sarrafi, and J.-C. Autran. Copyright 1994 by the American Association of Cereal Chemists, Inc.
Eight barley cultivars were grown and treated by the application of nitrogen at six different times and rates. Phosphate-sodium dodecyl sulfate extraction and size-exclusion high-performance liquid chromatography were used to separate different sizes of protein aggregates and monomers. Their compositions were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. It was found that the major protein fractions do not vary in the same way. The insoluble residue and the total protein content were significantly influenced by nitrogen fertilization. The size-exclusion high-performance liquid chromatography fraction F4, which is rich in C-hordein subunits, was also significantly influenced by nitrogen fertilization, while some others (F3 and F5) were essentially cultivar-dependent. Fraction F4 emerged as the best criterion for distinguishing between winter and spring barleys, and its quantitation could be recommended as a screening test of barley samples. This study provides a relevant approach for the understanding of the functional properties of hordeins in malting quality. It further supports the hypothesis that increased amounts of C hordeins impair malting quality by limiting water diffusion during the steeping phase.