Physicochemical stability of curcumin emulsions stabilized by Ulva fasciata polysaccharide under different metallic ions

The aim of this research was to investigate the effect of metallic ions (Na+, Ca2+, K+ and Mg2+) on the physicochemical stability of curcumin emulsions stabilized by Ulva fasciata polysaccharide (UFP). Mean droplet diameter, PdI, zeta-potential, microscopic morphology, and rheological properties of curcumin emulsion stabilized by UFP were investigated. The results showed that different metal ions had significantly different effects on the stability of emulsion. When the effect of Mg2+ was compared with others, it was found that Mg2+ had a pronounced effect on emulsion stability. As for z-average size and PdI, they changed significantly for metallic ions with higher valence. According to the rheology test, Ca2+ could mediate the gelation of UFP emulsions. Besides, with an increase of ionic concentration, the retention rate of curcumin was reduced. In comparison with gum Arabic, the UFP revealed better stability under different metallic ions and ionic concentration at same concentration.