title: Ultrarapid detection of bovine whey proteins in powdered soybean milk by perfusion reversed-phase high-performance liquid chromatography.
abstract: A perfusion reversed-phase high-performance liquid chromatographic method has been developed to simultaneously separate soybean and bovine whey proteins (alpha-lactalbumin and beta-lactoglobulins (A + B)) in a very short analysis time (approximately 5 min). The method consisted of a linear binary gradient water-acetonitrile-0.10% trifluoroacetic acid at a flow-rate of 3 ml/min, with the column thermostated at 60 degrees C, and ultraviolet detection at 254 nm. This method enables the rapid detection of adulterations of powdered soybean milks by addition of bovine whey proteins. When bovine whey proteins were too low to be detected by direct injection of the sample, a previous acidic precipitation step was required in order to concentrate these proteins. Quantitatve analysis of bovine whey proteins was also successfully performed. In fact, it was possible to detect about 1% and 1.3% of alpha-lactalbumin and beta-lactoglobulins, respectively, in a commercial powdered soybean milk in which these proteins were included in its formulation. Results were compared with those obtained by conventional reversed-phase high-performance liquid chromatography.
authors.affiliation: Departamento de Química Analítica, Facultad de Ciencias, Universidad de Alcalá, Madrid, Spain.
authors.forename: M C
authors.initials: MC
authors.lastname: García
authors.forename: M L
authors.initials: ML
authors.lastname: Marina
authors.forename: M
authors.initials: M
authors.lastname: Torre
mesh_terms: D000818:Animals; D002138:Calibration; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D007202:Indicators and Reagents; D007768:Lactalbumin / Q000032:analysis; D008894:Milk Proteins / Q000032:analysis*; D013025:Glycine max / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D000067816:Whey Proteins
chemical_list: D007202:Indicators and Reagents; D008894:Milk Proteins; D000067816:Whey Proteins; D007768:Lactalbumin