The most common method of characterizing the printability and material properties of a food ink for 3D printed foods composed of a novel mixture of two or more food materials is the trial-and-error method. Trail-and-error design is inefficient, both in terms of time requirements and wasted materials.  The use of a design tool to predict the nutritional information of a printed construct, its rheological properties, and manufacturing properties is necessary to aid designers during the preparation of novel food mixtures.  The tool may allow for varying food concentrations and shape design while outputting information helpful for users to determine printability and finetune nutritional content of 3D printed foods. Our research ventures into the creation of this design tool along with the library of food inks required for its extended use.

Our methodology for reliably printing foods informs the development of the design tool and beings with mixing food ingredients to form a novel food ink that is tested by printing and assessing its print quality based on its rheological measurements. The method consists of first printing basic designs with biomaterials known to print consistently. Chocolate, Marzipan, and Potatoes are commonly used for 3D printing food applications. Hence, the rheological properties (complex modulus and mechanical loss tangent) are tested for these commonly used materials as a baseline reference for what rheological properties are required for the food ink to have proper extrudability. Compared to a novel pumpkin biomaterial for 3D food printing (Figure 1A), it is found the pumpkin has a higher complex modulus and lower mechanical loss tangent than all other biomaterials, therefore motivating the addition of rheological agents to reach more favorable properties. Varied concentrations of corn starch and guar gum are added to the pumpkin; Addition of guar gum to pumpkin leads to the rheological properties of the mixture to be closer to the properties of the more commonly used food printing materials. (Figure 1B). These formulations of pumpkin are printed, and a 4% inclusion of guar gum provides the most consistent prints. A complex 3D object is prototyped with the 4% guar gum pumpkin material, therefore demonstrating the merits in using rheological properties to inform printability of novel food biomaterials. Using the data obtained from the experiments, our aim is to create a design tool that would help predict the printability of a novel composition of the food ink being used to print constructs while also outputting nutritional information relevant for personalized health.

The design tool requires the input of the type of material present in the food ink, percentage constituents of the food ink, along with the details of the shape that is printed using the food ink. It uses linear interpolation between rheological data obtained from experiments to calculate the rheological properties of the food mixture of varying concentrations. As the GUI has the data available for the impact of changes in additive concentrations from the previously conducted experiments, it is able to  predict the print volume and time required for the completion of the print according to the shape of the construct being printed. The percentage of the different materials is used to predict the Loss Tangent and Complex Modulus of the food ink along with the nutritional content of the printed construct (Figure 1C). This approach will greatly help finetune the printed food constructs according to the user-specific requirements along with the reduction of time spent investigating printability of novel mixtures.


Design Tool for Predicting Printability and Nutrition of Novel Food Inks Using Rheological Property Measurements

Division / Sponsors: 
Design Engineering Division and Computers & Information In Engineering Division


Paper Proceedings: https://asmedigitalcollection.asme.org/IDETC-CIE/IDETC-CIE2020/volume/83907

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