Recovery of functionally active trypsin inhibitor (SBTI) and lipoxygenase (LOX) from soymilk via multimodal technique

Commercially available epoxy activated polymers Immobeads and Dilbeads were functionalized to 1,2-amino alcohol derivatives and screened for binding and release of soybean trypsin inhibitor (SBTI) and lipoxygenase (LOX) in soymilk. Moderately hydrophobic polymer DILBEAD-VWR functionalized with diethylamine (DIL-DEA) was found to bind SBTI and LOX (3.5±0.3mg·g−1) without causing protein denaturation. Bound proteins were selectively released by changing the pH of eluting buffer. LOX was obtained in 70±5% overall yield with a purification factor of 5±0.5. The eluent containing SBTI was treated with bovine serum albumin coated polymer (Immobead 350) to obtain SBTI in 61% overall yield and a purification factor of 13.5. The recovered DIL-DEA polymer as well as BSA coated polymer were recycled at least 10 times without any appreciable change in performance. •Polymers with 1,2-amino alcohol groups with varying hydrophobicity are prepared.•Binding of trypsin inhibitor (SBTI) and lipoxygenase (LOX) in soymilk is studied.•Bound SBTI and LOX are selectively released by changing pH of eluting buffer.•SBTI is further purified 13 fold using BSA coated polymer.•The polymers are recycled several times.