Interfacial and emulsifying properties of the electrostatic complex of β-lactoglobulin fibril and gum Arabic (Acacia Seyal)

Abstract

Formation, interfacial and emulsifying properties of the electrostatic complex of β-lactoglobulin fibril (BLGF) and gum Arabic Acacia Seyal (AS) were investigated. Necklace-like soluble complex could be formed at pH 3.5, and its charge and interfacial properties depended on the BLGF content. With appropriate amount of BLGF (< 9.09 wt.%), the formed complex possessed a good dispersibility and surface activity. When excessive BLGF (9.09∼50 wt.%) existed, surface charge of the complex was gradually neutralized and aggregation occurred. Homogeneous oil-in-water emulsions could be stabilized by the complex and the droplet size decreased with increasing BLGF content. Higher content of BLGF (9.09∼50 wt.%) was detrimental for emulsification due to the aggregation of complex, and the formed emulsion tended to flocculate. Compared with AS, the complex formed emulsions were much more stable against heating (90 ℃, 30 min) and salting (200 mM NaCl) environments, and the emulsions were stable during long-term storage (46 days).