Something Borrowed (from Nature), Something Blue: Toxic Synthetic Food Dye may Soon be Replaced

Synthetic Blue Dye (#1 and #2) has a long history of holding the possibility of pernicious outcomes for some people when used in medicines, hospital pharmaceuticals and food. But all of that may soon be a thing of the past because scientists have uncovered a natural alternative to artificial blue food coloring in cabbage.


Blue pigments are rarely found in natural resources like plants and rocks, meaning that most blue products – including food, drinks, drugs, cosmetics and clothing – have to be made using synthetic blue dyes.

These synthetic dyes are typically made from petrochemicals, leading to concerns about their environmental impact and safety as food additives.

Scientists have spent decades searching for natural alternatives. The reason why the color blue is so uncommon in nature is because complex molecular structures are required to absorb the right wavelengths of light to give a blue appearance. But now scientists at the University of California, Davis have found a pigment in red cabbage similar to the artificial food coloring in FD&C Blue No. 1.

The discovery

The researchers found they could make larger quantities by treating the dominant red-colored anthocyanins present in red cabbage with a specially designed enzyme that turned them blue.

The team used the new blue pigment to make blue ice cream, doughnut icing and sugar-coated lentils. These products maintained their blue color while being stored for 30 days in ambient conditions.

What’s next?

Safety testing must be performed before the natural blue dye can be used in foods and medicines. 

Read the history of blue dye here.

Journal referencePamela R. Denish, et al. Discovery of a natural cyan blue: A unique food-sourced anthocyanin could replace synthetic brilliant blue, Science Advances, 07 Apr 2021: Vol. 7, no. 15, eabe7871. DOI: 10.1126/sciadv.abe7871