Colorful hair dyes from blackcurrants

It has been said that blondes have more fun, but thanks to some clever chemistry, the hottest hair hue could soon be blackcurrant. Researchers at the University of Leeds, led by Richard S. Blackburn and Christopher M. Rayner, have developed a natural hair dye made with anthocyanins extracted from the piquant berries’ skins (J. Ag. Food Chem. 2018, DOI: 10.1021/acs.jafc.8b01044). The skins are generated as waste from the production of Ribena, a blackcurrant cordial that’s popular in the U.K. Using a water-based process and special filters, the researchers were able to collect the anthocyanins. If applied at a pH of about 4, the dye will color hair red. Application at a pH of 6 leads to a blue color. Combining the anthocyanins with natural yellow dyes produces a range of browns. The color is semipermanent, washing out after about a dozen shampoos. Blackburn and Rayner believe the blackcurrant dyes offer a safer, greener alternative to hair dyes derived from petrochemicals. The blackcurrant-based hair color will be available this summer from the spin-off company Keracol and sold under the Dr. Craft brand.