Impact of dual-processed whole wheat flour on the physicochemical properties and digestibility of whole wheat bread.

Abstract

This study investigated the effects of incorporating heat-moisture and debranched treated whole wheat flour (HMD-F) on the physicochemical, textural, and digestibility properties of bread. Bread was prepared by the replacement of whole wheat flour with HMD-F at different concentrations (0%, 10%, 20%, 30%, 40%, 50%). The results demonstrated that HMD-F addition significantly improved dough water absorption, development time, stability, and viscoelasticity. However, it strongly inhibited starch gelatinization and retrogradation, reducing the peak and final viscosities by 82.8% and 79.1%, respectively, and decreasing thermal stability, with a gelatinization enthalpy (ΔH) of 1.67 J/g at 50% substitution. Regarding bread quality, HMD-F incorporation reduced specific volume, increased hardness, and darkened color, while baking loss decreased with increasing substitution, reaching a minimum of 11.21% at 50% substitution compared to 13.85% for the control (0% HMD-F). Notably, HMD-F enhanced nutritional properties: at 10% addition, resistant starch content increased to 41.59%, rapidly digestible starch decreased to 52.51%, and the estimated glycemic index (eGI) was reduced to 63.68, classifying the bread as a medium-GI food. The innovative combination of heat-moisture and debranched treatment, termed dual processing, promoted ordered crystallization of short-chain amylose and cross-linking with the gluten network, thereby synergistically improving anti-digestive properties and sensory quality. This approach provides a promising strategy for developing health-oriented staple foods.