Technological Optimisation of Gluten-Free Bread Through the Incorporation of Endocarp-Seed and Epicarp-Mesocarp Flours from Neltuma affinis Pods and Different Levels of Dough Hydration

Abstract

Gluten-free baked goods often exhibit technological deficiencies, characterised by reduced volume, dry and brittle crumb, cracked crusts, and shorter shelf-life. To overcome these limitations, the addition of novel raw materials combined with conventional flours and starches, has been proposed to improve technological and nutritional characteristics of gluten-free bread (GFB). The aim of this study was to evaluate the effect of adding different levels of endocarp-seed (ESF; 0–20 g·100 g-1) and epicarp-mesocarp (EMF; 0–20 g·100 g-1) flours from Neltuma affinis pods, together with varying levels of dough hydration (WH; 70–160 mL·100 g-1), on the fermentation behaviour and technological quality of GFB. A Box–Behnken experimental design and surface response methodology were applied. The results showed that the inclusion of ESF improved the fermentation time, crumb porosity and colour intensity; whereas EMF imparted a reddish colour to the formulations. Additionally, WH had a strong impact, increasing fermentation time, crumb moisture, weight loss and bread specific volume; thereby contributing to moister, softer, and more aerated crumbs. The optimal formulation to minimise firmness and lightness, and maximise bread specific volume, chroma and crumb porosity included 20 g·100 g⁻¹ ESF, 2 g·100 g⁻¹ EMF, and 126 mL·100 g⁻¹ WH. These findings highlight that different anatomical fractions from Neltuma affinis pods exert distinct effects on physicochemical characteristics of GFB, being ESF the most favourable among the fractions evaluated. Therefore, these flours represent an innovative alternative for the food industry, promoting both the valorisation and sustainable utilisation of this underutilised native species.