Soybean Trypsin Inhibitors: Selective Inactivation at Hydrolysis of Soybean Proteins by Some Enzymatic Complexes

Inactivation of the Kunitz and Bowman-Birk soybean trypsin inhibitors at hydrolysis of soybean proteins by enzymatic complexes was studied. These complexes are derived from king crab hepatopancreas, cod fish pyloric caeca, and a commercial enzymatic complex of protosubtilin. Analysis of the soybean protein hydrolysates showed that these enzymatic complexes completely digested the Kunitz trypsin inhibitor (60–70% of the total trypsin inhibitors) and had almost no effect on the Bowman-Birk trypsin and chymotrypsin inhibitor. All of the enzymatic complexes contain different sets of enzymes with different proteolytic specificity. This allow to make the conclusion that Bowman-Birk inhibitor is highly resistant to proteolysis and is not inactivated at enzymatic hydrolysis.