Complexation of locust bean gum and κ-carrageenan microgels, from aqueous phase to oil-water interface

Although polysaccharide microgels exhibit potential as clean-label emulsifiers, the stability of emulsions in commercial application is still a challenge. The current work points out that specific complexation between polysaccharide molecules and polysaccharide microgels can benefit the interfacial adsorption of polysaccharide microgels and emulsion stability. The complexation of κ-carrageenan microgels (KCMs) and locust bean gum (LBG) was investigated for the first time, which was evaluated by visual appearance, rheological behavior, thermal stability, and microscopic morphology. Results indicate the low concentration of LBG promotes the clustering of KCMs, whereas high concentration of LBG can envelop and segregate KCMs. Subsequent blending with LBG could enhance the interfacial adsorption of KCMs, and multi-layers are observed when LBG concentration exceeds 0.3 wt%. LBG can obviously decrease the emulsion droplets size and improve the storage stability of emulsions, KCMs + LBG (0.2–0.5 wt%) stabilized emulsions could keep stable after three consecutive freeze-thaw cycles. Based on the specific complexation between KCMs and LBG, the layer-by-layer emulsification could be achieved. This strategy can inspire other polysaccharide microgel emulsifiers, which could be a feasible solution for improving the stability of polysaccharides microgels stabilized emulsions.