Enhanced emulsion stability through synergistic interactions in ternary Maillard conjugates of soy protein isolate, maltodextrin, and gum Arabic

Abstract

This study examined the structural and functional properties of soy protein isolate (SPI) conjugates with maltodextrin (MD) and gum Arabic (GA) formed via the Maillard reaction under wet heating at 80 °C. Native SPI showed poor solubility (34.4 % at pH 7) and a limited emulsion stability index (ESI = 562.7 min). Binary conjugates improved specific properties but remained incomplete: S-M enhanced solubility (58.6 % at pH 7) yet exhibited creaming, whereas S-G suppressed creaming but maintained low solubility (38.4 % at pH 7). In contrast, the ternary conjugate (S-M-G) combined both advantages, maintaining high solubility (53.4 % at pH 7) and reducing surface hydrophobicity by 14.4 % compared with SPI. Emulsions stabilized by S-M-G showed the highest ESI (1434.7 min) and no creaming after five months of storage. These results indicate that ternary Maillard conjugation overcomes the intrinsic limitations of SPI and offers a promising strategy for developing stable natural protein emulsifiers.

Keywords: Dispersion stability; Grafting; Soy protein isolate; Storage stability; Surface hydrophobicity; Wet-heating.