Indigotine is a blue synthetic coal tar dye.
Animal studies in which high doses of indigotine were injected in rats over a long period of time led to inhibition of growth and development of cancerous tissue. Some animals suffered convulsive death immediately after injection. Similar studies in pigs showed alterations to blood composition and effects on the liver.
Cheeses, yogurt, sorbets, jams, fruit purées and fillings, processed seafood, ice cream
Indigo Carmine, FD&C Blue No. 2, Blue 2, E132