Stabilization of oil-in-water high internal phase Pickering emulsion by using 7S globulin/konjac glucomannan complexes: Rheology properties, stability properties and 3D/4D printing performance.

Food-grade compound-stabilized high internal phase Pickering emulsions (HIPPEs) have attracted considerable interest in the food industry and the field of functional foods. Nonetheless, challenges persist regarding the integration of active ingredients and the need for swift processing and shaping in food manufacturing. In this study, the effects of different konjac glucomannan (KGM) concentrations (0 %, 0.125 %, 0.25 %, 0.375 %, 0.50 %, 0.625 % w/v) on the gel network structure, rheology properties (shear-thinning behavior, viscoelasticity, and thixotropic recovery), stability properties and 3D/4D printing properties of HIPPEs stabilized with 7S globulin (7S) were investigated. KGM (≤0.375 %) facilitated the formation of gel network structure, thus hindering oil droplet aggregation. Moreover, the HIPPEs stabilized by 7S-KGM could be used as food-grade inks for 3D printing, thanks to their excellent solid-like viscoelasticity, moderate shear thinning behavior, and outstanding thixotropic recovery. The HIPPEs prepared with the 7S-KGM complexes exhibited the best performance, and the resulting 3D printed models demonstrated good precision and stability. Furthermore, the prepared HIPPEs demonstrated excellent heating stability and lipid oxidation stability. The results of 4D printing showed that the appropriate concentration of KGM could significantly enhance the density of gel network structure of printed samples, thus inhibiting the transfer of curcumin from the oil phase into the aqueous phase, which resulted in an inconspicuous change in the color of the sample. However, the KGM (>0.375 %) produced the opposite effect. These findings fully leveraged the advantages of personalized customization in 3D printing technology, enriching the application scenarios of HIPPEs in 3D printing.