Electrophoretic analysis of wheat and rye mixtures in meal, flour and baked goods

Starch gel electrophoresis of endosperm prolamines extracted with 2 M urea, provides distinction between varieties of either wheat or rye, but the major differences in general pattern type between all rye samples and all wheat samples offers a basis for distinction between the two cereals. The proportions of wheat and rye in a mixture can be determined by comparing relative areas of densitometric scans for standard mixtures with that of a sample for analysis, or by direct calculation from area ratios for pure wheat and rye. For baked products, extraction with urea containing a reducing agent is recommended. Electrophoretic patterns are altered both as a result of baking and of using the reducing agent, but distinction between wheat and rye is still possible.