Modulation of the emulsifying and foaming properties of pH-shifted rice glutelin by controlled thermal processing:...

This study employed controlled heat treatment (35-95 °C) to modify pH-regulated rice glutelin (RG), improving its emulsifying and foaming properties through enhanced interfacial adsorption. Zetasizer, solubility and FT-IR analyses revealed that the treatment reduced the average size, enhanced electrostatic repulsion and improved solubility of pH-shifted RG, while preserving the more random coil and lower α-helix content. Conformational flexibility and ANS measurements further confirmed that the treatment enhanced the conformational flexibility and surface hydrophobicity of pH-shifted RG, indicating improved interfacial activity compared to unheated sample. Notably, heating at 65 °C yielded the highest emulsifying and foaming properties due to minimized interfacial tension (40.86 and 7.7 mN/m), maximized elastic modulus (18.44 and 8.59 mN/m), and steepest E-π slopes (4.288 and 2.022) at air-water and oil-water interfaces. However, temperatures above 65 °C caused protein aggregation and reduced adsorption efficiency. Overall, this approach offers an effective way to improve RG interfacial properties.