EFFECTS OF EXTRUSION TREATMENT ON ENZYMATIC HYDROLYSIS PROPERTIES OF WHEAT GLUTEN

Abstract

ABSTRACT Degree of hydrolysis (DH), protein recovery (PR), Fourier transform infrared spectroscopy (FTIR), molecular weight distribution and amino acid composition were examined to investigate effects of extrusion treatment on Pancreatin‐induced hydrolysis properties of wheat gluten in the present study. Results showed that extrusion treatment had significant impacts on enzymatic hydrolysis properties of wheat gluten. It not only resulted in significant increases of 19.2% in DH after 36 h of hydrolysis and 13.4% in PR after 60 h of hydrolysis, but also changed considerably FTIR spectroscopy, molecular weight distribution and amino acid composition of wheat gluten hydrolysates. The conformational changes and structural rearrangements of wheat gluten treated with extrusion might modify the catalytic sites of proteases and be responsible for the improvement of enzymatic hydrolysis efficiency of wheat gluten. PRACTICAL APPLICATIONSThere were increasing interests in expanding the usage fields of wheat gluten, as it is available in large amounts and at relatively low cost. However, its usage was limited due to lack of some desirable functional properties. Although enzymatic hydrolysis is able to improve the solubility and develop the emulsifying and foaming properties of wheat gluten, the low enzymatic hydrolysis efficiency remains one of the major problems present in the industrial scale production. Therefore, increasing enzymatic hydrolysis efficiency of wheat gluten gets more important. Our results clearly showed that enzymatic hydrolysis efficiency of extruded wheat gluten was increased significantly. Results from this preliminary study will provide a better understanding on enzymatic hydrolysis mechanisms of extruded wheat gluten and allow the screening of pretreatment method to improve the enzymatic hydrolysis efficiency during the industrial scale wheat gluten hydrolysates production.