Exploring the integration of orange peel for sustainable gluten-free flatbread making

In response to the growing demand for sustainable and nutritious gluten-free (GF) products, this study explore orange peel by-products as a breadmaking ingredient of GF rice or corn flatbreads. The orange peel powder exhibited remarkable water retention properties attributed to its high dietary fiber content. Partial pregelatinization of rice (64 g/100 g) and corn (67 g/100 g) flour allowed obtaining doughs with sufficient consistency and extensibility to obtain GF flatbreads. The inclusion of orange peel powder (0-9 g/100 g) influenced the consistency and thermal behavior of the dough. Modifying hydration levels mitigated the hardness resulting from orange peel powder substitution, leading to improved folding properties. Final products exhibited enhanced nutritional profiles, including higher ash and dietary fiber content. The optimum nutritional and technological outcomes were observed when employing the maximum substitution rate of 9 g/100 g, along with adjusted hydration (164 g/100 g for corn and 169 g/100 g for rice), with notable emphasis on the improved extensibility of the final products. Compared to rice-based flatbreads, corn-based flatbreads displayed more uniform dough consistency, lower gelatinization enthalpy, higher yellowness, and decreased extensibility due to the stiffer dough texture. This study suggests that orange peel residue holds significant promise as a nutritional and technological enhancer for gluten-free flatbreads.