Improve the physical and oxidative stability of O/W emulsions by moderate solidification of the oil phase by stearic acid

Physical instability and oxidation were two of the most evident problems existing in food emulsions. In this research, a facile approach of solidifying the oil phase by stearic acid was adopted to overcome the above problems simultaneously, emphasising the effect of the oleogelation extent. Polarizing microscope, rheological analysis, and X-ray diffraction (XRD) were used to characterize the oleogelation of the oil phase, and droplet size, microscopic observation and peroxide value analysis were applied to evaluate the emulsion stability. Results showed that with moderate solidification of the oil phase (0.8%-1.0% w/v stearic acid in oil phase), the emulsions exhibited excellent physical stability under the stress of centrifugal force, high salt, and long-term storage. Moreover, the oxidative stability of the emulsions was improved simultaneously, that the increasing of peroxide value was slowed significantly. Excessive solidification (e. g. 3% w/v stearic acid) of the oil phase would weaken these advantages or even bring about opposite results, due to the destruction of the emulsion droplets by the excessive crystallization. Our results suggested that moderate solidification of oil phase would be a feasible and effective approach to improve the stability of o/w emulsions, which would be significant for the industrial-scaled production.

Automated summary

The study focused on enhancing the physical and oxidative stability of emulsions by moderate solidification of the oil phase, showing improved performance under stress conditions. Excessive solidification, however, led to adverse effects due to destruction of emulsion droplets. Moderate solidification was found to be a feasible and effective approach for industrial-scaled production.