Fabrication of telechelic DNA bridged food emulsion gel as edible ink for 3D printing

Interdroplet interactions affect the properties and textures of emulsions. In this study, we creatively introduced telechelic DNA to link the oil droplets directly at molecular scale to further improve viscoelastic properties of emulsions. A stable emulsion with 70% oil fraction was prepared by 40 mg/mL of whey protein isolate and peach gum polysaccharide complex (WPI-PGP complex). The addition of telechelic DNA (0.125 to 0.375 μM) made emulsion state from cream-like to self-supporting gel. Rheological experiments confirmed that the telechelic DNA could improve the yield stress, storage modulus/loss modulus (G’/G”) and apparent viscosity of emulsion gel in a concentration-dependent manner (0 to 0.375 μM). Inverted fluorescence images manifestly showed the interdroplet network of emulsion gel linked by telechelic DNA. For 3D printing, the emulsion gel with a higher concentration (0.375 μM) of telechelic DNA displayed a better surface quality and dimensional resolution, indicating an improved printability. Therefore, this study successfully designed a novel telechelic DNA-bridged emulsion gel, which showed great potential as edible inks for 3D printing.