Effect of wheat bran modification by steam explosion on structural characteristics and rheological properties of wheat flour dough

摘要

Steam explosion (SE) was applied to modify the chemical-physical properties of wheat bran and the effects of SE bran on structural and rheological properties of wheat flour dough were investigated. Results showed that SE modified wheat bran by facilitating the dissolution of soluble dietary fibers (SDF) and promoting its hydration properties. Substitution of SE bran in wheat flour dough mainly caused the competitive water sequestering effect. The effect promoted the partial dehydration of gluten and caused protein conformational changes of the collapse of beta-turns into beta-sheet structures. These phenomena demonstrated a more polymerized and stable gluten network formed, which inevitably affected dough rheological properties. The addition of SE bran caused some changes of dough farinograph property depending on the gluten content. It improved the dough stability by increasing the development time (DT) and decreasing the softening degree (D-s) at low-gluten content, while took the adverse effects at higher gluten content owing to the excessive water sequestering and dilution action of bran. Viscoelastic profiles confirmed that SE bran strengthened the dough elasticity by increasing the storage modulus (G') and loss modulus (G") and decreasing the loss tangent (tan delta) of dough at all gluten content. The results contribute to interpret the action mechanism of SE modification on cereals' brans and further guide the application of SE modification on cereals' bran processing and its flour products development.