Functional and technological effects of vegetable powders in gluten-free formulations

Vegetable powders are promising bakery ingredients, but their impact in gluten-free (GF) systems remains poorly characterized. This study assessed the effect of incorporating spinach, chard, kale, pak choi and artichoke powders into GF breads formulated with rice or maize flour. Dough properties were analyzed by rheology, Rapid Visco Analyzer pasting for swelling and thermal stability, and Differential Scanning Calorimetry for starch gelatinization. Bread quality was assessed by texture profile analysis, crumb color, moisture and slice morphology. In rice-based doughs, kale and chard increased viscosity by about 50% compared to the control, whereas both showed lower storage modulus (30%). Spinach enhanced cohesiveness in rice breads, while the lowest hardness was found in maize bread with kale (629 g) and rice bread with spinach (575 g). Crumb color changes were pigment-driven, with spinach and kale producing green hue shifts and maize masking carotenoid tones from pak choi. Correlation matrix analysis highlighted dough-bread associations, including RVA breakdown positively associated with hardness in rice breads and enthalpy related to loaf volume in maize breads. Principal component analysis revealed cereal-specific predictive patterns. Overall, whole-plant powders modulated GF bread texture, color and structure depending on cereal base and vegetable type, supporting nutritional and technological optimization strategies.