Selection of Commercial Enzymes for Soymilkcurd Production by Limited Proteolysis with Immobilized Enzyme Reactor.

Commercial proteases suitable for soymilk-curd production by limited proteolysis with immobilized enzyme reactor were selected from three plant and a microbial proteases. Limited proteolysis of soy-protein with the enzymes at 30, 5 and 0°C was examined by an electrophoresis. Two commercial preparations of papain and a preparation of bromelain, which were plant proteases, limitedly digested native soyprotein even under the low temperature conditions. The soy-protein solution and soymilk treated with the plant proteases at 5°C gave curd by heat treatment. The plant enzymes were immobilized on SP-Sephadex C-25. The immobilized enzymes digested the soy-protein similarly to the free enzymes. Soymilk-curd was also obtained from the soymilk hydrolyzed with the immobilized enzymes.