Structure and rheology of mixed hydrocolloid gels as model systems for food 3D printing

在下文中，我提出了一项长期研究计划，旨在开发食品添加剂制造的工艺-结构-性能关系。食品3D打印在“数字化美食”中得到应用，探索新的形状、味道、质地和创新食谱。然而，它最有趣的焦点可能是改善医疗保健，它可以根据老年人等个人需求调整食物的营养价值、形状和质地。正如美国宇航局所说，它需要“一流的食物流变学专业知识”，这表明它作为一项技术的重要性，可以帮助长期任务中的宇航员提供食物。我的团队在了解复杂流体的流变特性方面处于领先地位，我们最近在多糖基水凝胶的3D打印方面的进展代表了开展本研究计划中提出的工作的完美专业知识。主要目标是加深我们对食品3D打印材料行为的理解，更具体地说，是在水凝胶成型挤出中，以扩大其作为食品加工补充技术的潜在用途。本研究旨在利用多糖-蛋白质水胶体作为模型系统，并有助于对其大分子组装的基本理解。本研究计划的预期结果包括：(1)制定可打印性指数和(2)确定稳定打印结构的最佳参数。它将考虑通过多糖（复合碳水化合物）、蛋白质和纤维（不溶性纤维素添加剂）的组合来增加食用油墨的复杂性。最后，它将针对(3)建立关系，指导食品3D打印和开发多种增材制造方法。考虑到人口老龄化，这项研究计划对加拿大人的影响可能是相当大的。例如，打印食物泥可以帮助老年人咀嚼和吞咽问题（吞咽困难）和维生素缺乏。此外，使用适合儿童、孕妇或运动员个人状况、活动水平和个人偏好的食品成分为他们印制定制膳食，可有助于加拿大人口的全球健康和福祉。从长远来看，随着通过血液测试和先进的诊断工具获得个人生物特征数据，根据日常确定的需求和通过3D打印等食品自动化生产来控制维生素、营养素、过敏原、热量含量和份量将成为可能。最后，通过获得3D打印、流变学、理化表征、食品加工和批判性思维等行业所需的专业知识，为未来的食品行业培养高素质人才。这项研究的结果可能有助于加拿大发展这个有前途的新兴技术食品市场。

In the following, I propose a long-term research program seeking to develop process-structure-property relationships for food additive manufacturing. Food 3D printing finds applications in "digitalized gastronomy", with the exploration of new shapes, flavors, textures and innovative recipes. However its most interesting focus might be in improving healthcare, where it can adapt food nutritional value, shape and texture to individual needs such as those of elderly people. It requires "premier food rheology expertise" as stated by NASA, who signaled its importance as a technology that could help feeding the crew over long duration missions. My group is a leader in understanding rheological properties of complex fluids, and our recent developments on 3D printing of polysaccharide-based hydrogels represent the perfect expertise to carry out the work proposed in this research program. The main objective is to deepen our understanding of material behavior in food 3D printing, more specifically in hydrogel-forming extrusion, in order to expand its potential use as a complementary technology for food processing. The research proposed aims at using polysaccharide-protein hydrocolloids as model systems and contribute to the fundamental understanding of their macromolecular assembly. Expected results of this research program include (1) the development of a printability index and (2) the determination of optimal parameters to stabilize the printed structures. It will consider increased complexity of edible inks with combination of polysaccharides (complex carbohydrates), proteins and fibers (insoluble cellulose additives). Finally it will aim at (3) establishing relationships to guide 3D printing of food and develop multiple additive manufacturing methods. The impact of this research program could be considerable for Canadians, in view of the aging population. For example, printing pureed food-type could help seniors with chewing and swallowing problems (dysphagia) and affected by vitamin deficiencies. Furthermore, printing customized meals for children, expectant mothers or athletes using food ingredients adapted to their individual condition, activity level and personal preferences could contribute to global health and well-being of the Canadian population. On a longer term, as biometric data about individuals become available through blood tests and advanced diagnosis tools, it will become possible to control the vitamins, nutrients, allergens, caloric content and portion size according to daily determined needs and through the automated production of food such as 3D printing. Finally, highly qualified personnel will be trained for the food industry of tomorrow by gaining expertise in 3D printing, rheology, physicochemical characterization, food processing and critical thinking, all qualifications sought by the industry. Results from this research may help Canada to develop this promising emerging technological food market.