Want healthy Valentine’s day chocolates? We can print them

Rutgers scientists have created a low-fat chocolate recipe that can be printed on 3D printers in almost any shape one can imagine, even a heart.

The work heralds what the researcher hopes will be a new line of “functional foods”—edibles specially designed with health benefits. This is a way to make healthier chocolates more easily available to consumers.

Reporting in the journal Food Hydrocolloids, a Rutgers-led team of scientists described the successful creation and printing of a mixture producing low-fat chocolate—substituting fatty cocoa butter with a lower-fat, water-in-oil emulsion.

Qingrong Huang is a Rutgers School of Environmental and Biological Sciences professor. He said that while everyone loves chocolate, they are also concerned about their health. We created a chocolate that is both low-fat and that can be printed with a 3D printer. It is our first ‘functional’ chocolat.

Huang, the study’s author, stated that he is already working to reduce sugar in the new chocolate formula for low-sugar or sugar-free varieties.

Emulsions can be made by dissolving two liquids into small droplets. In emulsions, the two liquids will usually quickly separate—as is the case with oil and vinegar—unless they are held together by a third, stabilizing ingredient known as an emulsifier. An egg is used as an emulsifier to make a vinaigrette.

Cocoa butter, cocoa powder, and powdered sugar are the main ingredients in chocolate candy. You can also add any of a number of emulsifiers to make it even more delicious.

The scientific team tested different amounts of ingredients in a standard chocolate recipe to determine the optimal balance between liquids and solids for 3D printing. Researchers created an emulsion made from water and cocoa butter, which was then held together with gum arabic (an extract of the acacia tree) to replace the cocoa butter. To enhance the flavor, the researchers added golden syrup to the emulsion.

Huang stated that chocolate, as delightful as it can be, is an excellent material for food scientists to study.

Researchers examined the physical characteristics of printed chocolate using advanced techniques to examine the molecular structure as well as the physical properties. Huang explained that they were looking for the right level of viscosity to print and for the best texture and smoothness for a good mouthfeel. They experimented with many water-oil ratios before finally settling on one.

3D printing is the process of creating a physical object using a digital model. This is done by placing layers of material in rapid succession. Huang stated that the app on a mobile phone can program the 3D printer to create different shapes.

Ultimately, Huang said he plans to design functional foods containing healthy added ingredients—substances he has spent more than two decades studying, such as extracts from orange peel, tea, red pepper, onion, Rosemary, turmeric, blueberry and ginger—that consumers can print and eat.

Huang explained that 3D food-printing technology allows the creation of custom edible products with tailored taste and shape as well as optimal nutrition based upon consumer needs.