Stability, microstructural and rheological properties of complex prebiotic emulsion stabilized by sodium caseinate with inulin and konjac glucomannan

Abstract

The effects of inulin and konjac glucomannan (KGM) on the physical stability, rheological properties, and microstructure of prebiotic oil-in-water emulsions stabilized by sodium caseinate (CAS) were investigated. The emulsions were firstly analyzed by droplet size and creaming index. The results showed that inulin/KGM could enhance temporary network structures of continuous phase when high concentrations of KGM and inulin were added. High oil (>40%) input induced large droplet size of emulsions with low inulin/KGM ratios. Increased KGM content (inulin/KGM>2:0.1) could significantly decrease droplet size and enhance the creaming stability of emulsions. Rheological measurement and microstructure indicated that the influence of inulin and KGM on CAS stabilized emulsions was oil fraction dependent. Emulsions without any separation showed small droplet size and strong gel network as inulin/KGM was added (above the critical ratio of 2:0.1). The results showed that inulin and KGM have the potential to regulate the stability and rheological properties of emulsions, which may provide an interesting perspective in prebiotic emulsion with various purposes.