Novel food-grade water-in-water emulsion fabricated by amylopectin and tara gum: Property evaluation and stability analysis

To surmount the limitation of the instability of the currently reported water-in-water (W/W) emulsions, novel W/W emulsionss were constructed using amylopectin (AMP) and tara gum (TG) as the phases, and differently shaped ovalbumin (OVA) particles were used as stabilizers to improve the stability of W/W emulsions. Experiments displayed that the conformation of OVA could be changed by heating treatment, thus forming fibrous or spherical OVA particles that had the potential to stabilize TG-in-AMP (TG/AMP) emulsions. The emulsions had the best stability when the pH was 4 and the concentration of OVA particles was 3 %. Moreover, since ovalbumin fibril (OVAF) had better adsorption at the water-water interface than ovalbumin sphere (OVAS), OVAF-stabilized TG/AMP emulsion (OF-TE) had a relatively denser interfacial layer and exhibited more satisfactory ionic stability and physical stability than OVAS-stabilized TG/AMP emulsion (OS-TE). The rheological results demonstrated that OVAF and OVAS had little effect on the viscosity of TG/AMP emulsions. In brief, OVAF was more effective in improving the stability of TG/AMP emulsions than OVAS, and OF-TE did not show phase separation for at least 5 days. This study may be of great significance in improving the stability of food-grade W/W emulsions.