In situ crosslinking sodium alginate on oil-water interface to stabilize the O/W emulsions

It has been a great challenge of using natural polysaccharides to stabilize food emulsions, due to their poor amphiphilicity. In this study, a novel strategy of using polysaccharide to stabilize O/W emulsions was developed, through in situ crosslinking of sodium alginate on oil-water interface. During the emulsifying process, the acetic acid migrated across the interface, and induced the released of calcium ions, which immediately crosslinked the sodium alginate on interface. Results showed that the oil droplets were encapsulated in the integral polysaccharide shells. The droplet size of the emulsions located in the range from 20 to 200 μm. The concentration of sodium alginate and HAc, as well as the mixing rates were showed to be positively related with the thickness of the shell. However, excess calcium ions would disintegrate the shell structure. Additionally, the interfacial crosslinked sodium alginate stabilized emulsions exhibited excellent physical stability under centrifugating and freeze-thawing.