Preparation and Characterization of Coconut Oil Emulsions Stabilized by Cellulose Nanofibers

To achieve stable coconut oil-based emulsions, cellulose nanofibers (CNFs) were utilized as solid stabilizers, and the emulsions were prepared through a combination of homogenization and ultrasonication. The study examined various parameters, including microstructure, emulsification index, average particle size, Zeta potential, and centrifugal stability. Optimal conditions for CNFs concentration, sonication time, and oil phase mass fraction were determined through one-way experiments. The emulsions prepared under optimal conditions were also subjected to laser confocal microscopy (CLSM) observation and the effect of storage time on the emulsions. The results indicated that the highest stability of the coconut oil emulsion was attained with a CNFs concentration of 1wt%, a sonication time of 4 min, and an oil phase mass fraction of 10%. Under these conditions, the average particle size of the emulsion was 2.343±0.006 μm, the Zeta potential was −51.541±0.980 mV, and the instability index was 0.001. CLSM images confirmed that the emulsions were of the oil-in-water type. The rheological analysis revealed that these emulsions exhibited typical shear-thinning behavior and were predominantly elastic, with variations in solid particle concentration enhancing the gel strength of the emulsions. The prepared emulsions demonstrated excellent stability, remaining free from phase separation or sedimentation at room temperature for more than 6 months. This study can provide theoretical support for the construction of coconut oil emulsions in the food processing industry.