Rheological and pasting characteristics of wheat starch modified with sequential triple enzymes.

To gain desired viscoelastic properties of wheat flour and to expand the wheat flour current utility with more palatable foods, herein wheat starch, one of the important components of wheat flour, has been modified sequentially using β-amylase (BA), transglucosidase (TG) and pullulanase (PUL). The results show that compared to native starch, percentage of shorter linear chains (DP 6-12) significantly increased after the BA→TG→PUL treatment, resulting in lower relative crystallinity but with enhanced ordered structure. Compared to the native starch paste viscosity of 1632.98 Cp, the final viscosity of BA/TG/PUL-modified starch pastes reached the maximum value of 3132.01 Cp when the TG treatment time was 20 h, which indicated the paste viscosity increased by 91.80 %. Furthermore, BA/TG/PUL-modified starch pastes exhibit higher shear resistance and gel strength.