Combined effects of heating and epigallocatechin Gallate on emulsion stability of mung bean protein fraction: A structural perspective.

Mung bean protein has garnered increasing attention due to its sustainability, high nutritional value, and low allergenicity. To further explore its functional potential, this study investigated the effects of heating and epigallocatechin gallate (EGCG) on the structural and emulsifying properties of mung bean protein fraction (PRO). The results showed that elevated temperatures (≥70 °C) promoted the transition of interactions between PRO and EGCG from non-covalent to covalent binding. Under the combined treatment of high temperature (≥ 70 °C) and EGCG, native PRO aggregates unfolded and formed complexes with small particle size and high absolute ζ-potential. Among them, PRO-1.5E-70 °C (combined treatment of 70 °C and 1.5 mg/mL EGCG) exhibited the smallest particle size (56.42 nm) and the highest absolute ζ-potential (-17.62 mV), corresponding to an excellent emulsifying activity index (13.21 m2/g). Furthermore, the PRO-1.5E-70 °C emulsions remained stable for over 120 days without obvious phase separation (creaming index = 0), and exhibited excellent stability at various storage temperatures (4-55 °C). This improved stability may be attributed to the formation of a highly viscoelastic continuous-phase network that effectively inhibits droplet mobility and coalescence. This work provides a theoretical basis and practical guidance for the development and application of high-performance mung bean protein-polyphenol emulsion systems.