E101: Riboflavin

What is E101?

E101i is riboflavin in its free form, vitamin B2, as distinct from riboflavin-5'-phosphate (E101ii). It is an orange-yellow crystalline powder that is only sparingly soluble in water and sensitive to light.

Origin and production

It is mainly manufactured by fermentation using selected bacteria or fungi, some of which may be genetically modified, and can also be produced by chemical synthesis. Riboflavin naturally occurs in dairy, eggs, meat and green vegetables.

Why is it used?

It adds a yellow colour and often doubles as vitamin fortification. It is used in dietary supplements, instant noodles, cereals, sweetened and energy drinks.

Vegan, vegetarian and halal

Riboflavin from fermentation or synthesis is generally free of animal ingredients, but production details can vary, so vegan or vegetarian certification is the clearest confirmation.

Safety and regulation

Riboflavin is authorised in the EU as a food colour and was re-evaluated by EFSA, which found no safety concern at reported levels. Excess riboflavin is readily excreted and may colour urine bright yellow.

Common in