3D Printing Performance of Four Chromatic Mashed Potatoes: Structure and Functional Properties

The primary components and properties of food raw materials are crucial for processing high-quality 3D printed foods. Chromatic potatoes are rich in antioxidant active substances, which possess strong antioxidant and anti-tumor activities. However, their application in 3D printing has not been comprehensively studied. In this study, four kinds of chromatic potatoes—Heijingang, Hongmeigui, Jianchuanhong and Red potato—were used as raw materials to investigate the structure and accuracy of 3D printed products. The changes in physicochemical properties, phytochemicals, and antioxidant activity of the four chromatic potatoes after steaming and 3D printing were investigated. The results showed that total phenolic content of the four chromatic potatoes increased significantly, and total anthocyanin content of Hongmeigui and Heijingang also increased after steaming (p < 0.05). Notably, Heijingang demonstrated the highest antioxidant ability and had a significant inhibitory effect on HepG-2 cell proliferation, suggesting potential for functional food development. However, its high polyphenol content interfered with the formation of an ordered starch structure, resulting in weaker mechanical strength and severe deformation of printed products. In contrast, Jianchuanhong and Red potato exhibited higher mechanical strength and fluidity (high G′ and tan δ) as well as greater short-range order, resulting in better 3D printing performance and higher accuracy, making them more suitable for 3D food printing. This study offers a fresh theoretical foundation for the utilization of chromatic potatoes in 3D printed food.