Modifying Structure–Functionality of Common Bean ( Phaseolus vulgaris L.) Protein via Cold Atmospheric Plasma Processing and Maillard Reaction

Abstract

Structural and functional modifications of common bean (Phaseolus vulgaris L.) protein were investigated using cold atmospheric plasma (CAP) and Maillard reaction (MR) with pectin. CAP treatment (20 kV, 1–5 min) significantly enhanced protein solubility and emulsifying activity. Conversely, MR (90 °C, 0.5–3 h) reduced solubility and foaming properties but improved gelling capacity, achieving the lowest gelation concentration (LGC) at 2–3 h of heating. Conformational shifts in secondary structures (α-helix, β-turn, and β-sheet) were confirmed by FTIR and correlated with protein unfolding and structural modifications, as characterized by SDS-PAGE. Zeta potential measurements indicated that CAP improved colloidal stability, whereas extended MR heating decreased stability. These findings demonstrate that CAP is an effective nonthermal tool for enhancing protein functionality, while MR is better suited for developing stable gel-based food matrices, lowering the LGC from 8% to 5%.