How to realize the 3D printing of Okara ink without any additives

Currently,
food
3D printingThe research hotspots are mainly focused on the development of food materials. In view of the fact that a single food raw material cannot satisfy3D printingTherefore, various food additives are added to the food ink to change its rheological properties, so as to improve the printability of the food ink. However, the addition of food additives (such as hydrocolloids) can inhibit the flavor of the original food to a certain extent, and correspondingly change the texture of the original food. It is inevitable that some consumers like the unique flavor and texture of natural ingredients. Is there a way to achieve 3D printing without adding any food additives?

On November 8, 2021, in order to overcome the above-mentioned challenges, a new foreign research attempted for the first time without adding any food additives. By changing the particle size and concentration of food particles, it achieved okara (a kind of soybean side effect produced during the production of soy milk and tofu). Product) 3D printing.
The research was completed by researchers from Singapore University of Technology and Design and Nanyang Technological University. The related research is “3D Printing of Okara Ink: The Effect of Particle Size on the Printability.” The topic was published in the international journal ACS Food Science & Technology, and was selected as the front cover of the current issue (Volume 1, Issue 11, 2021).

Okara is a by-product of soybeans produced by filtering soluble components during the production of soybean milk and tofu. Okara is rich in nutrients and contains 44% dietary fiber, 22% protein and 10% fat (by dry weight).

In order to realize the reuse of bean dregs, the researchers collected the bean dregs as kitchen waste from a local soymilk supplier, dried and pulverized the bean dregs, and then used 500μm, 300μm and 100μm sieves to sieve the bean dregs powder. In order to distinguish the particle size of the bean dregs. Without adding any food additives, only add water to configure Okara ink with different concentrations (25%, 33%, 50% w/w), and then perform direct ink writing (DIW) 3D printing.

Research shows that particle size is an important variable that determines the rheological properties of Okara ink. When Okara powder particle size is less than 100μm and the concentration is 33%, its yield stress is 200±40Pa, storage modulus is 23300±300Pa, no particles The blocking phenomenon caused by agglomeration occurs, which can be used for 3D printing. The selected ink can maintain the printed structure without being deformed due to diffusion, and the researchers achieved 3D printed okara with different textures (such as hardness and adhesion) by adjusting the filling density of the 3D structure (Figure A below).

The researchers pointed out that the 3D printed okara products can be eaten directly or further
Post-processing
Processing, such as steaming, roasting and freeze drying. And the researchers demonstrated to us that the 3D printed bean dregs products were freeze-dried. After freeze-drying, they can be used as snacks that can be eaten in one bite. At the same time, the products have a longer shelf life due to dehydration (Figure B below).

In the literature, the hardness of common snacks like potato chips is about 140g. In this study, the maximum hardness of the 3D printed okara product is 47.00±4.58g (100% filling), but the hardness can be improved by post-processing such as baking or freeze-drying, so as to achieve a texture similar to existing snacks such as potato chips. .
In summary, in order not to add food additives (such as edible hydrocolloids), while retaining the original flavor and texture of the food, while achieving 3D printing, a granular food suspension can be prepared by changing the particle size of the food particles. 3D printing food ink.The principles and methods involved in the research can also be applied to other by-products and non-by-product edible materials, which will promote 3D food printing in
Medical treatment
Potential applications in health and food sustainability.

Paper link:

https://doi.org/10.1021/acsfoodscitech.1c00236

(Editor in charge: admin)