A group of scientists from ETH Zurich, Switzerland, and FHNW University of Applied Sciences and Arts Northwestern Switzerland, Windisch, has developed a process to make chocolate shimmer in rainbow colors without the addition of colorants. The chocolate seems to glow in the light through a surface imprint. A nanostructured pattern on the surface of the chocolate refracts the light in a special way and thus creates the iridescent color impression. Butterflies and beetles use the same principle for their iridescence.
The team has developed a mold that makes it possible to imprint more than one chocolate at a time. According to the researchers, their discovery is ready to be scaled up for industry. The scientists have filed a patent for the process, are in discussions with major chocolate producers, and plan to establish a spin-off company soon.
- Making chocolate colourful,
Michael Walther,
ETH Zurich News 19.12.2019