Study on hydrolysis conditions of flavourzyme in soybean polypeptide alcalase hydrolysate and soybean polypeptide refining process

Abstract

Soybean protein Alcalase hydrolysate was further hydrolyzed by adopting Flavourzyme as hydrolytic enzyme. The optimal hydrolysis conditions of Flavourzyme was that pH was 7.0 at temperature 50°C and E/S(ratio of enzyme and substrate) was 20LAPU/g. Bitterness value was reduced to 2 after Flavourzyme hydrolysis reaction in optimal hydrolysis conditions. The change of molecular weight distribution range from Alcalase hydrolysate to Flavourzyme hydrolysate was not obvious. DH (Degree of hydrolysis) of soybean protein hydrolysate was increased to 24.2% which was improved 3.5% than Alcalase hydrolysate. Protein recovery proportion was increased to 73.2% which was improved 0.8% than Alcalase hydrolysate. Soybean polypeptide Flavourzyme hydrolysate was decolorized with activated carbon which optimal dosage was 1.2% solution amount (w/w). Anion/cation exchange process was used in the desalination processing of soybean polypeptide. Ratio of anion resin and cation resin was 2:3(V/V). The volume of hydrolysate processed was 5 times as the volume of anion resin. Ash content of soybean peptide solution reduced to 2.11% (dry basis), salinity decreased by 86% after desalination processing.