Development of rheologically stable high internal phase emulsions by gelatin/chitooligosaccharide mixtures and food application

Gelatin (GE) modified by chitooligosaccharide (COS) through electrostatic interaction and hydrogen bond was applied to stabilize food-grade high internal phase emulsions (HIPEs) via a facile way. The influence of COS on rheological stability and practical food application of HIPEs was investigated. The interaction between GE and COS promoted a tighter connection between GE and COS, endowed the interfacial membrane with strong structure to anti-deformation, and prevented the accumulation of emulsion droplets by steric hindrance effect. Rheological analysis further proved that COS could lead to high viscosity, high elasticity, excellent oscillation performance, high recovery rate, great thixotropy and the strengthened structure of HIPEs, suggesting the outstanding rheological stability for three dimensional (3D) printing. Subsequent 3D printing on colored card and food confirmed that the obtained HIPE had good extrudability and printing performance. This study could provide important implications for the development of food-grade rheologically stable HIPE and promote the potential food application in rapid prototyping.