A Perfusion Reversed-Phase Chromatographic Method for Ultrarapid Determination of Soybean Proteins in Soybean Infant Formulas and Soybean Milks: Method Development and Validation

Abstract

Perfusion reversed-phase high-performance liquid chromatography (perfusion RP-HPLC) is applied for the first time to the determination of soybean proteins in commercial samples prepared from soybean protein isolate. A linear binary gradient of acetonitrile-water-0.1% trifluoroacetic acid at a flow rate of 3 mL/min and a temperature of 60°C is optimized to analyze soybean proteins in approximately 3 min. Direct injection of samples into the chromatographic system is possible by dissolving them in water. Quantitation of soybean proteins is achieved by the proposed method using a soybean protein isolate as an external standard. The method is validated and applied to the quantitation of soybean proteins in infant formulas and powdered and liquid soybean milks.