5D Food Printing with Color Change Induced by Probiotic Growth in a Starch-Protein-Based Gel System

Tea polyphenols and probiotic powder were incorporated into milk-enriched purple potato puree in order to investigate quality changes of the products printed using different ink formulations during the fermentation process. After the fermentation of the printed products containing tea polyphenols and probiotic powder, the number of probiotics increased and the growth of harmful microorganisms (mold as a model) was inhibited. Additionally, the growth of probiotics brought about the changes in pH in the printed samples, resulting in a controllable color change of the incorporated anthocyanin from purple to red. The textural properties (e.g., hardness and adhesiveness) were different with the difference in fermentation times, which were correlated with the dynamic change in probiotic count. This gave rise to the development of 5D food printing based on the dynamic change in the live cell count of probiotics.