Persimmon tannin can enhance the emulsifying properties of persimmon pectin via promoting the network and forming a honeycomb-structure

In the present study, multi-scale methods, including emulsifying capability evaluation and emulsion stability determination, were used to explore the effect of persimmon tannin (PT) on the emulsification performance of persimmon pectin (PP). A series of PP-PT solutions containing 10 mg/mL of PP and 0.05–2 mg/mL of PT were prepared and used to fabricate oil-in-water emulsions. Further, the potential influencing mechanism of PT on the emulsifying characteristics of PP was exploited by the Cryo-SEM morphology, interfacial tension, and interfacial dilatational rheology measurements. The results indicated that the emulsifying and emulsion-stability potential of PP was enhanced with the addition of high-level PT (1 and 2 mg/mL), reflected by the improvement in emulsifying capacity, droplet sizes (D32, D43, and particle size), TSI value, creaming thickness, and the strengthened tolerance to salt ions (100–1000 mmol/L NaCl and 100–500 mmol/L CaCl2), heating treatment (50–90 °C for 60 min), and accelerated destruction process (thermal cycling and accelerated centrifugation). However, PT in low concentrations (0.05, 0.1, and 0.2 mg/mL) displayed emulsion-damaging effects. In addition, high concentrations of PT (1 and 2 mg/mL) promoted the 3D-network structure, formed the honeycomb structure of emulsions and enhanced the viscoelasticity of the interfacial film to resist unfavorable factors. In contrast, the network structure and interfacial viscoelasticity deteriorated when low levels of PT (0.05, 0.1, and 0.2 mg/mL) were added. Overall, high levels of PT can be a cooperative agent for enhancing the emulsification properties of PP. Our data might provide a scientific basis for broadening the application of PP and PT as functional ingredients in the food industry.