Improved stability and mechanical properties of citrus pectin-zein emulsion gels by double crosslinking with calcium and transglutaminase

The low water solubility of zein severely limits its industrial application. In this study, the emulsifying performance and stability of zein were improved by electrostatically compounding different ratios of citrus pectin (CP) with zein to obtain zein-CP composite particles (ZCPs). When the mass ratio of CP to zein was 1: 2 (C1Z2), the composite particles showed the smallest particle size, and the C1Z2 stabilized Pickering emulsion (C1Z2-PE) exhibited excellent physical and environmental stability. The ZCPs stabilized emulsions were further cross-linked by transglutaminase (TGase) and Ca2+, resulting in the formation of emulsion gels with increased mechanical properties. Macroscopic and microscopic morphology analysis demonstrated the successful preparation of the emulsion gels. Through the rheological study and texture analysis, it was observed that the double cross-linked emulsion gels exhibited a remarkable improvement in apparent viscosity and gel hardness. This research offers a new strategy and technical reference for the development of new gel-based products.