The crude methanolic extracts of a single bean from samples of organic, natural or genetically modified (GM) soybeans [Glycine max. (Merrill) L.] were analyzed by direct infusion electrospray ionization mass spectrometry (ESI-MS). These extracts, containing
the most polar natural products of soybeans (free aglycones, monoglucosides, diglucosides and esters including isoflavones
and flavones) provide characteristic fingerprinting mass spectra owing to different proportions or sets of components. Spectra
distinctiveness is confirmed by chemometric multivariate analysis of the ESI-MS data, which place the three-types of beans
into well-defined groups. When ESI-MS is applied, these polar components constitute therefore unique chemotaxonomic markers
able to provide fast soybean typification.