Abstract: In this work, the effects of the amount and particle size of natural, extruded, and steam exploded wheat bran on the gelatinization characteristics of wheat flour with different gluten contents were investigated. The results showed that the peak viscosity, final viscosity and setback of wheat flour significantly decreased with the increase of wheat bran content (P < 0.05), while the gelatinization temperature and onset time increased quadratically, more significantly with the addition of extruded and steam exploded wheat bran relative to the natural one. The peak viscosity, final viscosity and setback of natural wheat flour with high and medium contents of gluten declined first and then rose with decreasing particle size of wheat bran, whereas the gelatinization temperature and onset time decreased continuously. The setback of low-gluten flour significantly changed with particle size of wheat bran in the range of 0.150–0.420 mm. There was no significant difference in the effect of the particle size of extruded and steam exploded wheat bran on the peak viscosity of medium-gluten flour (P > 0.05), while the peak viscosity of high-gluten flour was significantly influenced by the particle size of natural and steam exploded wheat bran (P < 0.05).

Key words: extruded bran, steam exploded bran, particle size, addition level, pasting properties