Improvement of Functionalities of Soymilk Residue Protein by Papain Hydrolysis

Protein was extracted at pH 9 from fresh soy milk residue (okara) received from soy milk factory, and was modified by papain hydrolysis was done at the concentration of 1 gm of enzyme per 100 gm of protein and incubated for 30, 60 and 90 mins The electrophoresis pattern showed a decrease in molecular size of the proteins by the enzyme hydrolysis. Surface hydrophobicity of papain modified okara protein was significantly increased with increase in reaction time. This indicated the unfolding of the molecule. The poor solubility of okara protein was clearly improved by partially hydrosis with papain, particularly at 90 min. Other functionalities such as emulsion activity and foaming properties of okara protein were also enhanced by papain hydrolysis.

Keywords: soy protein,  okara

Corresponding author: E-mail: cayongyuth@yahoo.com