Scientists Develop Structural Colour Coating for Chocolate
Researchers at ETH Zurich University have developed an iridescent coating for chocolate that doesn’t use artificial colourants. This taps into the growing concern amongst consumers surrounding their health and the environment, whereby more mindful approaches to colour, material and finish (CMF) applications are emerging.
The coating effect, which has a shimmering spectral quality, is created using the science of structural colour. Based on the phenomenon found in nature (see Bird Feathers Inspire Artificial Pigment), this method of colouration is the result of complex nanostructures designed to reflect light. As the light disperses, it creates intense and dazzling hues.
The team have formulated a way to imprint these light-refracting nanostructures onto the surface of the confectionery using a mould. This is similar to the method produced by Switzerland-based company Morphotonix – read more in Holographic Chocolate. ETH Zurich’s process is ready to be scaled-up for industry, and larger moulds are currently being developed.
As outlined in our Look Ahead 2020, structural colour is a promising alternative to conventional colouring methods, because it doesn’t rely on abundant chemicals or water. We’ve noticed a number of designers exploring it for different applications. See Structural Colour in Dutch Design Week 2019 and Elissa Brunato in 10 Next-Gen Sustainable Designers.