Comparative Analysis of Gluten-Free Flours on Dough Rheology and Texture

Thesis Abstract

Gluten-free reformulations offer a viable solution to gluten intolerance and celiac disease, yet their impact on dough rheology and sensory texture remains inadequately understood across diverse cereal-based flours. This study aims to comparatively analyze the rheological behavior and textural properties of doughs prepared from multiple gluten-free flours, elucidating how flour composition influences gluten-free bread quality. The specific objectives are to (i) quantify steady-state and dynamic rheological properties of doughs made from almond, sorghum, millet, and rice flours alongside a composite hydrocolloid system, (ii) assess textural attributes of baked products using instrumental and sensory methods, (iii) model relationships between flour composition, rheology, and texture using multivariate approaches, and (iv) identify flour-specific processing adjustments to optimize crumb structure and dough handling. The study adopts a comparative cross-sectional design conducted under controlled loading and baking conditions. The population comprises commercial gluten-free flours and laboratory-grade counterparts; a stratified sample of sixteen dough formulations (four flours × four controlled water absorption levels) and corresponding bread loaves were prepared. Data collection employed an array of instruments and techniques oscillatory rheometry (frequency and strain sweeps) to determine storage and loss moduli (G?, G??), steady shear rheometry for apparent viscosity, Mixolab profiles to assess dough development and breakdown, and dynamic dough temperature monitoring. Texture analysis included instrumental crumb hardness, cohesiveness, springiness, and chewiness using a Texture Profile Analysis, complemented by sensory evaluation with a trained panel of thirty tasters evaluating crumb grain, uniformity, moisture, and overall acceptability. For statistical analysis, analysis of variance (ANOVA) and multivariate regression were conducted to detect significant flour effects and interaction terms, with principal component analysis (PCA) used to reveal dominant factors driving rheological and textural variation. Regression models incorporated flour proximal compositions (protein, amylose, fiber, lipid content) and water absorption as predictors. The theoretical framework integrates the Network Dynamics Theory of dough systems and Food Structure Theory to interpret how biopolymer interactions, hydrocolloid addition, and starch–protein matrices govern viscoelastic responses and crumb architecture. It is anticipated that sorghum and millet flours will exhibit distinct viscoelastic signatures, with higher G?/G?? ratios under parallel conditions due to differing starch gelatinization and fiber interactions, while almond and rice flours will demonstrate weaker network formation unless optimized with hydrocolloids. The composite formulation is expected to partially recover dough strength but may increase crumb softness and moisture retention, affecting sensory acceptability. Anticipated findings include a set of significant flour-specific rheological profiles that correlate with crumb hardness and crumb grain uniformity, and identification of optimal water absorption ranges for each flour to balance handling and loaf quality. The study will contribute to knowledge by clarifying, for the first time across a standardized cross-section of gluten-free flours, how intrinsic flour composition and chosen hydrocolloids modulate dough rheology and resultant texture, providing a framework for tailored gluten-free dough formulation. Potential implications include actionable guidelines for bakeries and product developers to select flour types and processing parameters that yield desirable crumb structures and consumer acceptability while maintaining nutritional and labeling accuracy. The main conclusion is expected to emphasize that no single gluten-free flour delivers universal dough strength and crumb quality; instead, flour-specific rheological targets, coupled with precise water management and hydrocolloid strategies, are required to achieve optimized textural outcomes. Recommendations will include (i) flour-specific formulation guidelines for commercial gluten-free dough systems, (ii) standardized rheo-textural evaluation protocols for quality control, and (iii) further research into synergistic combinations of gluten-free flours with novel hydrocolloids and enzymes to broaden the parameter space for desirable bread characteristics.