Physicochemical, Rheological, and Sensory Characterization of Gluten-Reduced Cookies Enriched with Amaranth and Chickpea Flours

The global transition toward plant-based diets necessitates the development of sustainable, nutritionally enriched, and gluten-reduced bakery products. This study evaluated the techno-functional, nutritional, and sensory impacts of substituting wheat flour at levels of 30%, 50%, and 70% with a binary blend of amaranth (Amaranthus caudatus) and chickpea (Cicer arietinum) flours in short-dough cookies. Dough’s thermo-mechanical behavior was characterized using the Mixolab Chopin+ protocol and correlated with Texture Profile Analysis (TPA) and consumer acceptability (n = 60) via Principal Component Analysis (PCA). Results revealed that the 70% substitution level (T3) significantly modified dough rheological behavior; the thermodynamic dilution of the gluten network and competitive hydration led to reduced dough stability (5.40 min) and restricted starch gelatinization (C3 = 0.916 Nm). Despite these rheological limitations, T3 demonstrated the highest protein density among the formulations tested, achieving 14.61% crude protein and 2.18% ash. Notably, the significant increase in instrumental hardness (68.09 N) in T3 corresponded with the highest overall acceptability score (4.07 out of 5.0). Multivariate analysis indicated that dough rheological instability does not necessarily limit final product acceptability in non-fermented matrices. These findings provide useful insights for the rational design of high-protein, plant-based functional snacks.