Effect of gelled phases on the relevance of double emulsion gels for probiotics encapsulation, rheological properties, and stability

Abstract

This study aimed to develop a stable double emulsion gel (DEG) based on whey protein cold-set gelation of the external water phase and carnauba wax-based solidification of the oil phase as a potential delivery system for probiotics in high-protein food products. The effect of the gelation of different phases on the microstructure, gel properties, and stability of DEGs under storage and freezing–thawing conditions and the viability of L. plantarum loaded in the inner water phase of DEGs were evaluated. The oil phase crystallization allowed the formation of stable DEGs during storage, showing negligible changes in consistency index, G′, and particle size after 56 d of storage and under four freeze–thaw cycles. The gelation of both the oil and external water phases allowed a stronger gel network formation, with a six times lower creaming index than non-gelled double emulsions. All samples demonstrated that the encapsulation of L. plantarum into the inner water phase of the DEG is beneficial for the storage stability of probiotics.