Multicriteria Quality Indices as a Tool for Estimating Consumer Desirability of Gluten-Free Bread Enriched with Chestnut Flour

The aim of this study was to develop multicriteria quality indices for gluten-free bread enriched with chestnut flour and to determine whether an index based only on physicochemical and textural attributes could approximate the consumer desirability ranking of bread formulations. This approach was intended as a practical tool supporting quality assessment, rather than as a replacement for sensory evaluation.

The analysis was conducted using data from formulations containing 0, 5, 10, 15, and 20% chestnut flour. Partial indices were calculated for texture, physicochemical properties, colour, and sensory quality. These were then combined into an integrated quality index and a physicochemical-textural index excluding all sensory variables. The direction of desirability for each attribute was defined according to its technological relevance. Lower hardness, gumminess, chewiness, and specific mass were treated as favourable, whereas higher loaf volume, porosity, springiness, and cohesiveness were considered beneficial. Variables with less straightforward technological interpretation were used cautiously or retained only for supplementary analyses.

The integrated quality index ranked the 5% formulation highest, followed by 10%, 15%, 0%, and 20%, with index values of 0.729, 0.672, 0.527, 0.429, and 0.181, respectively. The physicochemical-textural index produced the same ranking for the three highest-rated formulations, with values of 0.646, 0.584, and 0.482 for the 5%, 10%, and 15% formulations, respectively. Its agreement with consumer desirability was high at the ranking level, with Spearman’s rho = 0.90 and Pearson’s r = 0.80.

Feature reduction analysis showed that four measurements, TPA hardness, volume per 100 g, porosity, and crumb lightness L*, were sufficient to approximate the full quality ranking, with MAE = 0.035, RMSE = 0.046, R² = 0.943, and Spearman’s rho = 1.00. Further validation is required using independent baking trials, different chestnut flour sources, and varied baking conditions.