A natural blue dye that can be used as an alternative to synthetic blue colouring has been discovered by a team of researchers, including chemists at the University of California, Davis.
The new cyan blue colouring has been extracted from red cabbage. Extracts from the vegetable are already widely used as a source of natural food dyes – called anthocyanins – particularly reds and purples.
Research on isolating blue anthocyanin from red cabbage has been ongoing. Scientists at the Mars Advanced Research Institute and Mars Wrigley Science and Technology, in collaboration with the UC Davis Innovation Institute for Food and Health; The Ohio State University; Nagoya University, Japan; the University of Avignon, France; and SISSA University, Italy, have been working on the project for the last decade, but, until now, only managed to isolate the dye in tiny amounts.
Professor Justin Siegel at the UC Davis Department of Chemistry and Innovation Institute for Food and Health, Biophysics PHD candidate Pamela Denish and postdoctoral researcher Kathryn Guggenheim, screened millions of enzymes for candidates and tested a small number in the lab until they found one that would efficiently convert the natural blue dye from the cabbage in higher quantities.
“Blue colours are really quite rare in nature – a lot of them are really reds and purples,” said Pamela Denish when discussing the project at UCDavies.
“Having the right blue colour is also important for mixing other colors, such as green. If the blue isn’t right, it will produce muddy, brown colors when mixed,” added Professor Siegel.
Siegel and Denish have now founded a startup company, Peak B, to develop the technology for commercial applications. The new natural blue dye could replace synthetic colouring in food, such as sweets, drinks, pharmaceutical products, clothing and cosmetics.