Effects of powder-added phase on emulsifying properties of avocado powders under acidified and salted conditions

Abstract This work aimed at clarifying the effects of the powder-added phase (water or oil) on the emulsifying properties of avocado powder under various pH (4.0, 5.5, and 7.0) and salt (0 and 1 wt%) conditions. After analyses of colloidal properties of the powder aqueous dispersions, interfacial and emulsifying properties of avocado powder were evaluated in the powder-in-water (p/w) and powder-in-oil (p/o) systems. Under all the aqueous conditions, the avocado surface-active components adsorbed more quickly and densely to the oil-water interface to form more elastic adsorbed layers in the p/o systems than the p/w systems, which could be attributed to the solubilized polar lipids and/or the non-hydrated and non-ionized insoluble particles in the oil phase, resulting in higher accessibility to the interface. Consequently, finer emulsions exhibiting higher stability against flocculation and coalescence were obtained in the p/o systems compared to the p/w systems. Moreover, the p/w emulsions were more sensitive to the environmental changes. These results suggest that the desired emulsifying properties could be achieved by changing the powder-added phase.