Characterization and quantitation of soybean proteins in commercial soybean products by capillary electrophoresis

Capillary electrophoresis was applied for the first time to determine soybe an proteins in commercial soybean products. The most suitable conditions fo r the analysis of these products in less than 7 min were 0.05 M phosphate b uffer (pH 8) with 1 M urea; detection wavelength, 254 nm; applied voltage, 20 kV; and temperature, 30 degrees C. Quantitation of soybean proteins was achieved using referenced conditions by means of the method of standard add itions, using as standard a soybean protein isolate. This method was valida ted and applied to the quantitation of soybean proteins in commercial produ cts derived from soybean protein isolate and soybean seeds.