3D Printing with Food: Chinese Researchers Experiment with Lemon Gel & Potato Starch Base  

Most of the world is well aware by now that 3D printing is about far more than printing out your favorite Star Wars figures and key chains bearing the logos of your favorite sports teams. From building rockets to human tissue, this technology is very serious business—and it continues to make so many impacts around the world that we simply aren’t surprised anymore as one new innovation after another is presented. There is still plenty of room for fun though, and we have seen this demonstrated repeatedly in the world of food and cooking.

In using 3D printing with cooking, those coming up with new concoctions can experiment affordably and quickly—along with personalizing a multitude of different items from popsicles to chocolate to gluten-free recipes, and far more. The research and development continues around the world. Now, in China, a research team has discovered that lemon juice gel may be a very suitable ingredient for 3D printing; in fact, it may be used as a building block for high-tech recipes. Coupled with potato starch, the team found that the mixture allowed for ‘suitable 3D printing of designed objects.’ The lemon juice gel behaves almost like fudge would, allowing for the same texture and enticing chewiness consumers see in food products.

From the researchers’ paper: Different geometrical shapes of 3D printed lemon juice gel samples at different potato starch concentration (A = 10 g/100 g, B = 12.5 g/100 g, C = 15 g/100 g, D = 17.5 g/100 g, E = 20 g/100 g).

The Jiangnan University team explained their findings in a recently published paper, ‘Investigation on lemon juice gel as food material for 3D printing and optimization of printing parameters,’ authored by Fanli Yang, Min Zhang, Bhesh Bhandari, and Yaping Liu. While 3D printed properties of food were part of the research, the team was also very concerned with a more technical angle: nozzles. They examined 3D printing nozzles for food using the lemon and potato starch base, testing nozzles in terms of their height, width, rate of extrusion, movement, speed, and more.

“After a lot of experiments in this study, it is considered that the nozzle height is suitable to be same with that of the nozzle diameter, which could not be regarded as a key factor that affects print quality. Under the condition of the same nozzle diameter and nozzle height, the essential reason for the effect on the printing is likely to be the mismatched extrusion rate and printing speed,” state the researchers in their paper.

“In an ideal printing process, the extruded material has the same diameter as the nozzle considering there is no shrinking/swelling or expansion, and nozzle height should be as small as possible to ensure that the material can be attached to the previous layer and to avoid the inaccuracy caused by the delayed deposition. Therefore, the nozzle height should be equal to the nozzle diameter as well as the single layer height.”

Geometrical shape of printed lemon juice gel samples with different nozzle diameter (A = 0.5 mm, B = 1.0 mm, C = 1.5 mm, D = 2.0 mm).

The team measured rheological properties, performed a texture profile analysis, and then experimented with 3D printing. The team found that the rate of extrusion and the speed of the nozzle had an effect on 3D printing; for example, high extrusion led to wavy lines, while low extrusion rates led to discontinuous lines that could cause collapse. Ultimately, their goal was to 3D print with a smooth texture.

“The nozzle diameter (1 mm), the extruded rate (24 mm³/s) and the nozzle movement speed (30 mm/s) were the optimal parameters to provide well printed lines and to obtain exquisite products. What’s more, as a gel product, the success of lemon gel in 3D printing provides some guidance for other gel and starch products in 3D printing,” concluded the researchers.

Discuss in the 3D Printed Food forum at 3DPB.com.

Pictures of some products printed at 24 mm3/s extruded rate, 30 mm/s nozzle moving speed and 1.0 mm nozzle diameter (A. Anchor, B. Gecko, C. Snowflake, D. Ring, E. Tetrahedron).