Influence of Wheat Starch on the Structural Changes and Size Distribution of Gluten Induced by Adding Wheat Bran Dietary Fiber

This study investigates the particle size distribution and structural changes in the gluten system with and without starch induced by adding wheat bran dietary fiber (WBDF). The results show that adding WBDF tends to disturb the particle size distribution of gluten considerably and causes changes in the hydrophobic group microenvironment. The presence of starch can reduce the destructive effects of gluten by forming a more open but solid gluten matrix, which led to larger-sized particles. Moreover, the gluten-starch system exhibited a significantly higher surface hydrophobicity value of 3694.4 but a lower fluorescence intensity possibly due to the quenching effect. Both systems had similar zeta potentials ranging from 17.4 to 18.4mV, suggesting little impact of WBDF and starch on gluten electrostatic interactions. There results indicate that the changes in the gluten protein are determined not only by the amount of WBDF but also by the cooperation of starch.