In this study, the effects of pH (2.5, 6.5 and 7.8) and potato flake content (15%, 19%, 23% and 27%) on the properties of mashed potatoes (MP) were studied in terms of moisture distribution, rheological properties, texture properties and 3D printing performances. Results showed that the potato flake content was positively correlated with apparent viscosity, storage modulus (G′), and loss modulus (G″), while negatively correlated with tanδ and relaxation time (T₂). As the content of potato chips increased, the shape fidelity of MP increased after printing. The addition of citric acid increased MP's apparent viscosity, G′, hardness and gumminess, thus increasing its capacity to be self-supportable performance after deposition, while an opposite trend was observed when sodium bicarbonate was added. A dual-extrusion printer was furtherly used to manufacture a colorful 4D ready-to-eat food in terms of spontaneous color change by using anthocyanin-rich purple sweet potato puree and MP. Results indicated that the color change of MP was significantly correlated with the pH value and the potato flake content.

Industrial relevance

This work extends the conventional 3D printing of single material to multi-material, and potentially provides a new view on how to produce colorful food products by 4D printing in terms of spontaneous color change of 3D printed multi-material products.

中文翻译：

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自发变色的土豆泥/紫色地瓜泥的4D打印

在这项研究中，从水分分布，流变学方面研究了pH（2.5、6.5和7.8）和马铃薯片含量（15％，19％，23％和27％）对土豆泥性能的影响。特性，纹理特性和3D打印性能。结果表明，马铃薯片含量与表观粘度，储能模量（G'）和损耗模量（G”）呈正相关，而与tanδ和弛豫时间（T ₂）呈负相关。）。随着马铃薯片含量的增加，印刷后MP的形状保真度增加。柠檬酸的添加增加了MP的表观粘度，G'，硬度和胶粘性，因此增加了其沉积后自支撑性能的能力，而当添加碳酸氢钠时观察到相反的趋势。通过使用富含花青素的紫色甘薯原浆和MP，自发变色，进一步使用了双挤压打印机来制造色彩鲜艳的4D即食食品。结果表明，MP的颜色变化与pH值和马铃薯片含量显着相关。

行业相关性

这项工作将传统的3D打印从单一材料扩展到了多种材料，并且就3D打印的多种材料产品的自发变色而言，可能为如何通过4D打印生产彩色食品提供了新的视角。