E101: Riboflavin

What is E101?

Riboflavin (E101) is vitamin B2, a natural yellow-orange compound that glows bright yellow under ultraviolet light. As a food additive, E101 covers riboflavin itself and its more water-soluble phosphate form.

Origin and production

Riboflavin is found naturally in milk, eggs, meat and leafy greens. For industrial use it is mostly produced by fermentation with micro-organisms such as bacteria or fungi, sometimes genetically modified strains, and can also be made by chemical synthesis.

Why is it used?

It is added to give a yellow colour and, in many cases, to fortify foods with vitamin B2. It appears in instant noodles, sweetened and energy drinks, cereals, sauces and dietary supplements.

Vegan, vegetarian and halal

Riboflavin made by fermentation or synthesis contains no animal material and is generally suitable for vegans and vegetarians, but the fermentation medium or carriers can vary, so vegan certification is the most reliable confirmation.

Safety and regulation

E101 is authorised in the EU as a colour and was re-evaluated by EFSA, which concluded there was no safety concern at the levels used. Separately, riboflavin is a recognised essential vitamin.

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