Effects of wheat cultivar, bran concentration and endoxylanase on the thermomechanical, viscoelastic and microstructural properties of whole wheat flour dough

Abstract

Globally, it is challenging to promote the market of whole wheat product due to its undesirable product quality issues. To overcome this remarkable challenge, this research was to work on the constructive strategies for mitigating the negative impact of wheat bran. As such, the objective of this research was to investigate how the wheat cultivar, bran concentration and endoxylanase affected dough thermomechanical properties, viscoelasticity and microstructure by a combined use of mixolab, rheometry, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). A cultivar-dependent discrimination for the bran tolerance was observed to suggest the suitable wheat cultivars for whole wheat manufacturing. Bran addition positively affected dough mechanical and viscoelastic properties, i.e., larger dough mechanical weakening (C2) and gel strength, and it negatively affected starch gelatinization (C3) and retrogradation (C5). However, the main conclusions are below. The endoxylanase was incorporated to invert the bran impact on the above properties of dough. Endoxylanase was also used to develop a better integrity of gluten network, larger coverage of starch granules and even distribution of gas cells. Outcomes from this work will provide a practical guidance for improving the high-fibre product quality and promoting its market growth.