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

Abstract

AbstractThe 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.Practical ApplicationsThe potential applications of (water‐in‐oil‐in‐water [W1/O/W2]) double emulsions in food industry are limited by their low stability, including the weakness of the thin liquid oil film and the low thermodynamic stability of oil globules. The combination of oleogels and hydrogels could effectively improve the stability of double emulsions through the reinforcement of the oil film and the confinement of oil globules. This work provides a feasible method to improve the stability of (W1/O/W2) double emulsions, obtaining an applicable delivery system for hydrophilic active ingredients in food industry. The stable double emulsions could be used to encapsulate and control the release of hydrophilic bioactive ingredients and protect sensitive bioactive ingredients from chemical degradation. Otherwise, this system might achieve the co‐delivery of hydrophilic ingredients and hydrophobic ingredients.