Impact of red kidney bean flour substitution on the nutritional, physicochemical, and functional properties of gluten-free noodles

Red kidney beans ( Phaseolus vulgaris L .) are a rich source of protein, dietary fiber, and bioactive compounds, making them a promising ingredient for functional food development. This study evaluated the impact of red kidney bean flour substitution (10–50%) on the nutritional, physicochemical, and functional properties of gluten-free noodles. Increasing red kidney bean levels resulted in reduced peak viscosity, breakdown, final viscosity, and setback, reflecting alterations in starch-protein interactions. Thermal analysis showed elevated gelatinization temperatures and decreased enthalpy values, indicating modifications in starch crystallinity. Color analysis revealed a darker, more reddish-yellow hue (decreasing L*, increasing a*, b* values) as red kidney bean content increased. Red kidney bean substitution significantly enhanced protein, ash, fiber, flavonoid, and phenolic contents, with noodles containing 50% red kidney bean flour exhibiting the highest total amino acid and mineral contents. Antioxidant activity improved proportionally with red kidney bean contents. Increasing red kidney bean levels resulted in low glycemic index and high resistant starch. Gluten-free noodles fortified with 20% red kidney bean flour exhibited optimal quality while significantly enhancing nutritional profiles for healthier gluten-free alternatives. These findings establish red kidney bean flour as a sustainable and functional ingredient for developing nutrient-enriched gluten-free noodles, catering to health-conscious markets.