Fabrication of novel W/O/W emulsion gels using beeswax stabilized W/O: Preparation, characterization and co-delivery of phycocyanin and astaxanthin

Double emulsions (DEs), one of the most promising dispersion systems, have attracted much attention in the food industry. However, instability and the need for synthetic surfactants hinder the application of DEs. The development of clean-label DEs with good stability remains a challenge. Herein, novel DE gels (DEGs) with water-in-oil-in-water morphology were developed by combining multiple gelation and emulsification processes, which can stabilize the dispersion system without the synthetic surfactants used in conventional emulsions. Gelatin and beeswax were used to gelatinize the internal aqueous and oil phases respectively. Sodium caseinate acted as the external aqueous phase emulsifier, while a blend of gellan gum (GG) and sodium alginate (SA) was introduced to create DEGs. The networks formed by SA and GG in the water phase inhibited the movement of droplets in the emulsions and improved their stability. The DEGs can withstand up to five freeze-thaw cycles and at least 100 d of storage. In addition, the textural properties of DEGs were characterized and the results suggested that DEGs could be used as a cheese simulant. DEGs could be used as carriers for the co-delivery of phycocyanin and astaxanthin. Their encapsulation efficiency was greater than 90%. Furthermore, in vitro digestion showed that DEGs significantly improved the bioavailability of astaxanthin and phycocyanin, which increased from 18.5 ± 0.15% and 16.3 ± 0.45% to 43.2 ± 0.35% and 41.6 ± 0.5%, respectively. In conclusion, we have demonstrated a novel strategy for the preparation of clean-label DEGs, which could be used as a carrier for the co-delivery of hydrophilic and hydrophobic substances.