Oil-water interfacial dual-phase synergistic adsorption of capsanthin-cyanophycin in gelatin based high internal phase emulsions for multi-nozzle 3D printing

Gelatin based nanoparticles was prepared by sodium trimetaphosphate (STMP) for stabilizing and fabricating high internal phase emulsions (HIPEs), and cyanophycin and capsanthin were single/dual-encapsulated in emulsion systems. The characterization of FTIR, XRD, TGA, zeta potential, particle sizes, dilatation rheology and AFM indicated that the phosphate groups of STMP could react with side chain groups of gelatin and chitosan to form nanoparticles, and enhance the thermal resistance. The nanoparticles could form strong membrane on the oil-water interface, which prevents stratification and precipitation of HIPEs, and promotes high centrifugation stability and freezing-thawing stability. The functional HIPEs with single encapsulation of medium-content cyanophycin or capsanthin have excellent colors, shear thinning performance, structure reversibility, mechanical strength, elasticity and strong network systems with small emulsion droplets; however, the mixed purple HIPEs illustrated the relative weak network structure and the low final strain recovery rates with the enlarged emulsion droplets. On another hand, the simultaneous load of cyanophycin and capsanthin in emulsion systems could produce bright purple HIPEs based on Subtractive Color Principle, and HIPEs possess the outstanding rheological characteristics and the structured systems with small emulsion droplets. The outstanding extrudability and excellent combinational 3D printability of functional HIPEs suggest the great potential in personalized, innovative food production.