'Where's the blue food?' Scientists find source for natural blue food dye in red cabbage

Food scientists who've long been searching for a natural alternative for blue artificial food dye have found a pigment they could work with in red cabbage.

Concerns about a possible link between behavioural problems such as hyperactivity or inattention in some children and artificial food dyes led many food manufacturers to go on the hunt for natural alternatives. 

Some colours were easy to replace, like turmeric for yellow or beets for red, but finding a non-purplish natural source for the colour blue has always stymied food scientists. 

Now a team of scientists partially funded by Mars Wrigley, the company that makes M&Ms, says it's found a way, thanks to a pigment called an "anthocyanin" in red cabbage. Their study was published in the journal Science Advances. 

Pam Denish, a biophysics PhD candidate at the University of California, Davis and lead author on the study said in an interview with Quirks & Quarks host, Bob McDonald, the reason a natural blue has been such a challenge to find is because it's so rare in nature. 

The anthocyanin they found in red cabbage was close to the cyan blue they were looking for, but not quite perfect.  So the researchers decided to try a strategy found in some blue flowers when anthocyanins are combined with a metal ion, like aluminum.

Once they tried that, they got the blue they wanted, but since that pigment is only found in very small concentrations in red cabbage, the researchers needed a way to scale it up.

They found their answer with an enzyme that was able to convert other anthocyanins in red cabbage into the one they needed, so now it's more feasible to produce a natural blue dye at a mass scale in a cost effective manner. 

Produced and written by Sonya Buyting