Linking rheology and printability of a multicomponent gel system of carrageenan-xanthan-starch in extrusion based additive manufacturing
Linking rheology and printability of a multicomponent gel system of carrageenan-xanthan-starch in extrusion based additive manufacturing
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DOI：
10.1016/j.foodhyd.2018.08.026
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发表时间：
2019-02-01
影响因子：
10.7
通讯作者：
Zhang, Min
中科院分区：
文献类型：
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作者：
Liu, Zhenbin;Bhandari, Bhesh;Zhang, Min
3D食品打印是一项新兴技术，有可能影响食品制造业。食品油墨的流变性是其3D打印成功的关键。然而，在食品体系中，流变性和3D打印适宜性之间的关系还没有明确定义。本工作制备了卡拉胶-黄原胶-淀粉凝胶模型体系，用于挤压型3D食品打印机。将3D打印过程划分为三个阶段，并确定了每个阶段对应的油墨流变性，即挤出阶段(屈服应力、粘度和剪切变稀特性)、恢复阶段(剪切恢复和温度恢复特性)和自支撑阶段(复模数G*和室温屈服应力)。最后，从打印线/五角星(一维、一维结构)到打印网格支架(二维、二维结构)再到打印圆柱体(三维、三维结构)，系统地研究了模型油墨的3D打印适宜性。结果表明，在K-卡拉胶油墨中添加淀粉和黄原胶可提高油墨的凝胶化温度(T)、粘度(在剪切速率0.01-100 1/S范围内)、屈服应力G*、增强剪切稀化(触变性)行为和降低弹性模量(温度恢复)的时间依赖性。屈服应力(应力扫描测试中G‘(弹性模数)等于G’(粘性模数)的交叉点)和剪切稀化行为(粘度随剪切速率增加而降低)的流变响应与油墨的挤出性密切相关。油墨的胶化温度(T胶凝)和时间相关行为(胶凝时间，T凝胶)显著影响其印刷性能和保形性能。墨水的机械强度对于自给自足是很重要的，特别是对于3D结构。从这项研究中获得的见解可以为改善使用亲水胶体作为打印助剂的食品的3D打印性能提供指导。
3D food printing is an emerging technology with a potential to influence the food manufacturing sector. Rheological properties of food inks are critical for their successful 3D printing. However, the relationships between rheological properties and 3D printability have not been clearly defined in food systems. In this work, a gel model system composed of carrageenan-xanthan-starch was prepared for an extrusion-based 3D food printer. The 3D printing process was divided into three stages and the corresponding rheological properties of inks for each stage were determined, namely extrusion stage (yield stress, viscosity and shear-thinning behaviour), recovery stage (shear recovery and temperature recovery properties) and self-supporting stage (complex modulus G* and yield stress at room temperature). Finally, 3D printability of the model inks was systematically studied starting with printing lines/pentagram (one dimensional, 1D structure) to printing lattice scaffold (two dimensional, 2D structure) and finally printing cylinders (three dimensional, 3D structure). Results demonstrated that addition of starch and xanthan gum in k-carrageenan based inks increased inks' gelation temperature (Tgelation), viscosity (within shear rate of 0.01-100 1/s), yield stress, G*, enhanced shear-thinning (thixotropic) behaviour and reduced time-dependence of modulus (temperature recovery). Rheological responses of yield stress (cross-over point where G' (elastic modulus) equals to G'' (viscous modulus) in the stress sweep tests) and shear-thinning behaviour (viscosity decreased when shear rate increased) were closely related to ink's extrudability. Inks' gelation temperature (Tgelation) and time-dependent behaviour (gelation time, tgel) significantly affected their printability and shape retention performance. The mechanical strength of the ink is important to be self-supporting, especially for 3D structures. Insights achieved from this study could provide guidance on improving 3D printability of foods that use hydrocolloids as a printing aid.