In the United Kingdom, scientists at the University of Leeds are working to extract natural dye from blackcurrant waste generated in the manufacturing of Ribena, a popular English soft drink.
Chemists Richard Blackburn and Chris Rayner have patented the process, which is capable of producing a range of hair colors and lasts 12 washes.
“After being pressed, the skins remain as a waste product,” Rayner tells The Journal. “They have very high concentrations of anthocyanin, and represent a sustainable supply of raw material because of how much blackcurrant cordial we drink.”
Synthetic hair dyes are often made from petrochemicals and have the potential to cause severe allergic reactions.
“Because of issues and concerns around conventional dyes, we wanted to develop biodegradable alternatives that minimize potential risks to health and offer consumers a different option,” Blackburn adds.