Application of citrus fibre in gluten-free bread

Growing concerns about global food waste have encouraged the development of strategies to repurpose agro-industrial by-products into value-added food ingredients. One such approach involves the use of dietary fibre extracted from fruit residues, which has demonstrated potential for improving the functional properties of gluten-free baked goods. Gluten-free bread, in particular, often suffers from poor texture, low moisture retention, and reduced shelf life due to the absence of gluten.

This study investigated the incorporation of citrus fibre—derived from freeze-dried orange peel and a commercial fibre source—into gluten-free bread formulations at levels of 1%, 3%, and 6% (w/w flour basis). The effects on moisture content, crumb structure, and technological attributes were evaluated.

The chemical composition of freeze-dried orange peel was analyzed by determining its moisture content, protein concentration, using the Kjeldahl method, fat content, via Soxhlet extraction, and total carbohydrate and dietary fibre content. Technological properties, including water absorption capacity (WAC) and water swelling capacity (WSC), were also assessed for both fibre types.

Chemical analysis of freeze-dried orange peel revealed that it consists mainly of carbohydrates—74.87 g/100 g. The protein and fat content was 6.75 g/100 g and 3.31 g/100 g, respectively. Experimental trials demonstrated that citrus fibre significantly enhanced water-binding capacity, leading to improved crumb softness and overall bread quality. Among the tested concentrations, a 3% addition yielded the most favorable outcomes, offering an optimal balance between textural softness and crumb elasticity. Conversely, higher concentrations (6%) adversely affected the bread’s volume and contributed to a denser, less appealing texture.

These findings support the use of citrus fibre as a functional ingredient in gluten-free bread, aligning quality enhancement with sustainable food system goals.