A soy protein material having a very low isoflavones content and a high
saponins content is produced by a process that involves removal, by
adsorption, of isoflavones from a soy protein material obtained by
removing fiber from soy flour or flakes. The soy protein material also
has a high Nitrogen Solubility Index ("NSI"). The low isoflavones, high
saponins soy protein material has at least about 55.0 wt. % protein, less
than about 200 .mu.g/g isoflavones of total dry matter and at least about
1000 .mu.g/g soyasapogenols of total dry matter. The process for
producing the low isoflavones, high saponins soy protein material
involves removing fiber from a defatted soybean material and obtaining a
liquor that is subsequently pasteurized. Next, sugars and other small
molecular weight components are optionally removed from the liquor using
membrane separation to increase the protein content of the final
material. The resulting liquor or retentate is subjected to adsorptive
removal of isoflavones, and is optionally pasteurized and spray dried.