Improved stability of (W1/O/W2) double emulsions based on dual gelation: Oleogels and hydrogels

The objective of the present study was to improve the stability of (water-in-oil-in-water) double emulsions by dual gelation, including the gelation of lipid phase through oleogels and the gelation of continuous aqueous phase through hydrogels. Glycerol monostearate (GMS) could be used to form the oleogels and improve the stability of primary emulsions and double emulsions through reinforcing oil film. However, the redundant GMS crystals in both the oil phase and the continuous phase could cause the destabilization of double emulsions. The double emulsions reinforced by oleogels were successfully encapsulated in Ca-alginate hydrogel beads, and this encapsulation would not influence the integrity of double emulsions. The redundant GMS crystals might cause the leakage of the inner aqueous phase in the encapsulation process, and this leakage was more likely to happen during the mixing step, rather than the crosslinking step. Ca-alginate hydrogel beads were conducive to the confinement of the encapsulated oil globules.