Researchers at ETH Zurich developed a way of making chocolate shimmer with color without coloring agents or other additives.
The project was announced in December, and it involves structural colour – called so because the colour is derived from an interaction of light with the physical structure of a system. This is similar to what a chameleon does—that is, using the structure of its skin to scatter a particular wavelength of light.
Alissa M. Fitzgerald, the founder of MEMS product development firm AMFitzgerald, explained that Iridescence in nature (like that inside oyster shells and on the wings of butterflies) requires nanoscale patterns in the form of lines, holes or plates. She added that to create iridescent chocolate, the researchers created a nanotech chocolate mould, using e-beam lithography for etching lines of about 100 nm wide on a glass or silicon wafer.
The ETH researchers believe in getting their technique for colouring chocolate out of the laboratory and into the mass market. Meanwhile, during the COVID-19 pandemic, some technology professionals have been creating new rainbow chocolates.
Fitzgerald said that combining nano- and micro-technology fabrication techniques with atypical materials like food, fabric, paper, and plastic would lead to some fascinating new products and improve or enhance existing products.
(Editors note. As a separate read to this article, we wanted to include a reference to a page about the current opinion on the effect of nanoparticles on the body. Protagonists point to the fact that we have been eating particles at a ‘nano-level’ for many years – the homogenization of milk produces them, for example.
Nano-sized particles move through the body in ways that are currently not fully understood. They are able to pass through membranes for example. This effect made them exciting for researchers who at the turn of this century were working on ways to deliver beneficial, even life-saving drugs, direct to the source using a nano-level payload.
The Hong Kong Center for Food Safety has a short article that summarises the challenges. In short, while having shimmering chocolate is fun, it’s worth being aware of the current science behind the health of this technology)