Simultaneous separation of soya bean and animal whey proteins by reversed-phase high-performance liquid chromatography. Quantitative analysis in edible samples.

A reversed-phase high-performance liquid chromatography method was developed successfully for the simultaneous and rapid separation of the main soya bean proteins (globulins) and animal whey proteins (alpha-lactalbumin and beta-lactoglobulin). This method consisted of a linear gradient of two mobile phases (0.1% trifluoroacetic acid in water and 0.1% trifluoroacetic acid in acetonitrile). For the first time, soya bean globulins were separated from animal whey proteins. The analysis time for this separation was 20 min, eluting soya bean globulins in the first 10 min. The method was applied to quantify soya bean proteins in soya bean commercial milks with the possibility of detecting the presence of animal whey proteins. Adulteration of a powdered soya bean milk by animal whey proteins was detected. The possibility of detecting the presence of soya bean proteins in animal milks was also studied.