Color/aroma changes of 3D-Printed buckwheat dough with yellow flesh peach as triggered by microwave heating of gelatin-gum Arabic complex coacervates

Feasibility of using microwave heating as a stimulus and gelatin-gum Arabic-oil complex coacervates microcapsules as a stimulus-response material to realize color and aroma changes of 3D-printed buckwheat dough containing yellow flesh peach was explored. The morphology of microcapsules prior to printing exhibited a spherical multi-core structure with oil embedded. Addition of different mass fractions of microcapsules increased the storage modulus and loss modulus of the dough, but yielded no significant effect on its viscosity. After 3D printing, the shape of the microcapsules in the dough changed to be fusiform. Upon microwave heating, the microcapsules in the dough were gradually destroyed, with the embedded oil released. Addition of microcapsules increased a* value of the dough, especially upon microwave heating. Contents of (E)-cinnamaldehyde, which is the aroma compound, increased more than 2-fold after 4 min of microwave heating, while the original aroma of yellow flesh peach dough remained unchanged. Addition of 0.5%, 1%, 5% microcapsules could also significantly improve the printing performance. Gelatin-gum Arabic-oil complex coacervates microcapsules could be a potential material to induce color/aroma changes and used in food 3D printing, thus providing another alternative for 4D food printing.