Effect of inulin on rheological, textural, and structural properties of brown wheat flour dough and in vitro digestibility of developed Arabic bread

摘要

The brown wheat flour (BWF)-based Arabic bread was fortified with chicory-derived inulin. The objective of this work was to assess the influence of the inulin concentration (1.25 to 5%) on the rheological, textural properties, and fermentation efficacy of enriched BWF dough. Farinographic measurement established that only 3.75% BWF can be substituted by inulin in a dough formulation, which resulted in lowering the water absorption capacity. The peak gela-tinization temperature, T_p detected at 74.4 °C by rheometric measurement, which increased linearly with increasing the inulin concentration. The elastic modulus (G'), however, differed significantly among doughs with the addition of inulin. The dough hardness and compressibility increased as a function of inulin concentration. TPA measurement indicated that the Arabic bread fortified with 3.75% inulin was the best in texture. The addition of inulin improved the volume of CO_2 generation in the yeasted dough. The distribution of starch particles on the top layer of bread surface was visualized through SEM. In-vitro digestion and steady-flow measurement of the BWF/inulin bread digesta exhibited a slow digestion and an increment in the apparent viscosity against the control bread, which further confirmed potential health benefits of the developed Arabic bread.