Citrus fiber for the stabilization of O/W emulsion through combination of Pickering effect and fiber-based network

Abstract

In this study, oil-in-water emulsions stabilized by citrus fiber were prepared and characterized. We found that citrus fiber can produce stable gel-like, surfactant-free O/W emulsions with microscale droplet sizes at fiber concentrations upon 2% (W/V) using 25% (V/V) oil. The interfacial framework, citrus fiber partition between the continuous phase and state of the droplets of emulsions were visualized by confocal laser scanning microscopy (CLSM), confirming that in addition to Pickering stabilization, the citrus fiber-based network also contributed to stabilization of the emulsions. The citrus fiber-stabilized emulsion is typical non-Newtonian fluid and its interfacial viscosity is not influenced obviously by changing pH from 2 to 10, ionic strength of NaCl from 0.00 to 1.00 mol/L or temperature from -20 to 70 °C. The acquired findings in this study show that citrus fiber can fabricate Pickering emulsions with excellent stability and solve the problem of resource waste during the pectin produce process.

Keywords: Citrus fiber; Microstructure; Network; Pickering emulsions; Rheology.