An integrated process for obtaining oil, protease inhibitors and lectin from soybean flour

An integrated process has been developed to obtain oil and to remove/purify two antinutritional factors namely, soybean trypsin inhibitor and soybean agglutinin from soybean flour. Three phase partitioning of soybean flour was carried out by simultaneous addition of t-butanol (1:1, v/v) and ammonium sulphate (30%, w/v) to soybean slurry and 85% w/w oil could be recovered in this step. Three phase partitioning followed by immobilized metal affinity chromatography resulted in 90% and 93% yields with 26- and 15-fold purification for soybean trypsin inhibitor and soybean agglutinin, respectively. Both of these antinutritional factors gave significant purification on SDS–PAGE.