Exploration of Calocybe indica mushroom phenolic acid-kidney bean protein complex: Functional properties, amino acid profiles, in-vitro digestibility, and application in vegan product development

The study evaluates the interaction between Calocybe indica mushroom polyphenols (phenolic acid) and kidney bean protein (KBPM), aiming to enhance vegan food quality. The mushrooms exhibited a carbohydrate content of 3.65%, an antioxidant activity of 55.04 ± 0.17%, and a phenolic content of 4.86 mg GAE/g. Caffeic and cinnamic acids were identified through high-pressure liquid chromatography. Various concentrations of KBPM were tested at phenolic acid concentrations of 0.025, 0.050, 0.1, 0.2, 0.4, 0.8, and 1%, among these, KBPM 0.2 demonstrated the highest binding efficiency of 99.40 ± 0.05%. Notably, this complex improved the protein's functional properties, such as solubility by 11.43%, water and oil holding capacities by 10.62% and 22.04%, and emulsion capacity and stability by 3.69% and 5.83%, respectively, compared to the native protein. The protein-phenolic acid complex also enhanced thermal stability, surface charge, amino acid content, and reduced particle size compared to native protein. These enhancements also improved protein digestibility and sensory attributes in a fruit-based smoothie.