Fabrication of flavour oil high internal phase emulsions by casein/pectin hybrid particles: 3D printing performance

In this study, three-dimensional (3D) printable oil/water (O/W) high-internal-phase emulsions (HIPEs) (internal phase fraction = 75%) were fabricated using casein (3% w/v)/pectin (1-5% w/v) hybrid particles with flavour oil. The morphologies of the HIPEs, revealed by confocal laser scanning microscopy (CLSM) and cryo-scanning electron microscopy (cryo-SEM), indicated that the casein/pectin hybrid particles were mainly distributed on the interface of oil droplets. Additionally, the results of rheological and gel-strength measurements indicated that the viscosity (ranging from 1316.51-0.21 to 4301.84-0.79 Pa.s) of HIPEs increased with increasing pectin content (from 0% to 4% w/v), and the gel strength of printed HIPEs increased (from 10.37 to 21.19 g) with increasing pectin (from 1% to 5% w/v). The developed HIPEs were applied for 3D printing and the thus-printed objects could adequately maintain the designed shape and structure. The developed 3D printable HIPEs have excellent potential applications in the food, medical, and cosmetic industries.