Regulation of <i>Pleurotus geesteranus</i> protein particle characteristics on the microstructure and rheology of their W ₁ /O/W ₂ double emulsions

Abstract In the present work, the properties of Pleurotus geesteranus protein isolate particle (PPIP) were adjusted by changing the pH and salt concentration. The PPIP with different characteristics were used to prepare W 1 /O/W 2 double emulsions, aiming to control its microstructure and rheological properties. Adjusting the pH from 5.0 to 3.0 and 7.0 resulted in PPIP exhibiting a decrease in average particle size, oil-water contact angle ( θ o/w ) and interfacial tension, and an increase in net charge. Such PPIP were successfully used to fabricate W 1 /O/W 2 double emulsions with a gel-like network. At pH 5.0, double emulsions showed the highest inner aqueous phase content and gel strength. With an increase in salt concentration (0–500 mM), the particle size of PPIP gradually increased, while their zeta potential continuously decreased, and W 1 /O/W 2 double emulsions were prepared. However, the inner aqueous phase content, apparent viscosity, storage/loss modulus gradually decreased with an increase in salt concentration.