3D Printing, which is a kind of Additive Manufacturing Technology, has now
entered in the field of food processing and has also drawn attention of many researchers.

In 21st century where everything has been computerized, why should making of food continue with traditional cooking methods?

Though traditional methods have their own advantages but still they are tedious and time consuming.

That is where 3D food printing comes in the picture to offer us highly customized and personalized food with plenty of attractive 3-dimensional shapes.

One of the major advantages of additive manufacturing over subtractive manufacturing is that it brings down the reduction in material wastage to almost zero level.

How does it work??

A 3D printer can be regarded as a robot that is instructed by a digital file of 3D graphic model.

This graphic model of an object is generally created using Computer Aided Design (CAD) software such as Auto Cad, Solid Edge, Solid Work etc.

The CAD drawing is converted to the standard tessellation language (STL) format. This STL format file is transferred to computer system that operates the 3D printer.

The same computer also has a pre-installed slicing software which is sort of specific coding. Its function is to break the 3D model into 2- dimensional layers.

The printer is instructed by the slicing software to construct these 2D layers one on the top of other until the 3D object is created.

Another important aspect of this process is feeding the right kind of material in the right form and at appropriate temperature.

It becomes very easy when you want to make something from plastic by a 3D printer.

The most common plastic used in 3D printing is ABS filaments (Acrylonitrile Butadiene Styrene) in wired form. But it becomes the most difficult when material is food stuff.

Food Formulation

Food formulation is the most complex and difficult aspect of producing edible 3D printed objects.

This is where a food technologist or a food engineer plays a vital role in making a successful 3D food product.

The formulation of food ink should be in such a way that after printing, it must gain physical stability and at the same time, it should be nutritionally rich and tasty.

One who formulates the food for 3D printing should have a precise and thorough knowledge of rheological, nutritional, and biological properties of particular food material.

Customization or personalization is one of the characterized advantages of 3D food printing. It allows us to formulate the nutritional value of the product according to the deficiency of micronutrients in a particular age group.


Types of 3D Food Printing

Each 3D printer is designed for a specific type of material. So when we talk about food material 3D printing, it can be classified into three categories:

  1. Extrusion-based Printing
  2. Inkjet Printing
  3. Binder Jetting

Extrusion-Based Printing

In extrusion-based printing, the material (solid or paste with low viscosity) is loaded into a plastic or metallic syringe. And then, it is pushed out through a micro nozzle at constant pressure.

Application of constant pressure can be done in one of these three ways: pneumatic, piston-driven or screw-driven.

First two techniques can be used for low viscous material whereas the last one is desirable for higher viscosity material.

The 3D printer deposits the melted filament by layer, each layer on top of the others, to build the object in 3D. 

When one layer is complete, the tray holding the object lowers very slightly and the extrusion process resumes, depositing a new layer of melted filament on top of the previous one. 

Deposited layers are fused together as the melted plastic quickly solidifies to form a solid three-dimensional object.

This type of printing method is used for dispensing macromolecules such as hydrogel or polymer. Some of the edible hydrogel are polysaccharides, protein and lipids.

Inkjet Printing

An inkjet printer dispenses low viscosity (generally liquid) material in the form of stream of droplets falling through micro nozzle connected to thermal or piezoelectric head.

In the case of the thermal head, the print head is electrically heated to establish pulses of pressure. These pulses of pressure push the low viscous material in the form of droplets from the nozzle.

In case of piezoelectric head, the material is made to fall continuously in the droplet form by vibrating it at certain frequency.

This method is not suitable for creating complex 3D shapes because it uses only liquid materials.

Binder Jetting

In binder 3D printing, the inkjet nozzle applies a fine dry powder and a liquid glue, or binder, that come together to form each printed layer. Binder printers make two passes to form each layer.

The first pass deposits a thin coating of the powder, and the second pass uses the nozzles to apply the binder.

This method allows us to use combination of liquid and powdered materials.

Powder materials used are Sugars and starch mixtures.
And, the liquid binding agents could be corn syrup, soy sauce etc.

Reference

A Review of 3D Food Printing Technology


3D Printing of Food in food industry

3D Printed Chocolate by Cadbury Australia

In a world premiere, CADBURY DAIRY MILK launched the very first CADBURY DAIRY MILK milk chocolate 3D Printer, in celebration of World Chocolate Day on July 7, 2019.

LINK


How Hershey’s is Using 3-D Printers to Make Chocolate Kisses