Investigation of 5D printing of children food based on anthocyanin microcapsules and spontaneous changes in probiotics

This study explored the characterization of the microcapsules and their addition's impact on printing characteristics, and tested the spontaneous changes in pH, probiotic and mold counts, flavor, texture, and color of the printed samples over time, dynamically indicating the growth level of probiotics through color change. The results showed that SPI (soy protein isolate) and CS (chitosan) achieved efficient encapsulation of blueberry anthocyanins through composite coagulation, the encapsulation rate of the microcapsules was 87.89 ± 1.16 %, with the microcapsules exhibiting irregular fragment-like structures. The addition of microcapsules had minimal impact on the rheological properties, moisture distribution, and printing performance of the printing materials, the optimal addition amount of microcapsules was 4 %. As the culture time evolved, the spontaneous growth and metabolism of probiotics produced organic acids such as lactic acid, amino acids, peptides, and other metabolic products, leading to decrease in pH of the printed samples. This affected the coagulation of casein and the gelation of starch in the printed products, improving the texture characteristics of the printed samples. The color of the printed samples gradually turned red during the cultivation process. The encapsulation effect of the microcapsules enhanced the time-dependency of color response, with the change in a* value of the printed samples correlating with the change in probiotic counts, achieving correlation of 0.92. The 4D color change effectively indicated dynamic changes in life. The design of the internal structure via 3D printing affected the rapid proliferation of probiotics in the printed samples, thereby manifesting as differences in texture, pH, visual sensory, and flavor.

Industrial relevance

This study provides new ideas for the application of microencapsulation and probiotics in the field of food additive manufacturing. Anthocyanin microcapsules and probiotics were utilized as smart-responsive materials and life-active substances for food printing, respectively. In this study, the color, flavor, and texture changes of 3D printed samples were induced by the efficient 4D printing synergistic probiotic fast-addition strategy. The color and texture changes of the printed samples can be a better indicator of life dynamic changes. This opens up new possibilities for the personalization of novelty foods for children.