E106 - flavin mononucleotide
What it is and how it is used
Flavin mononucleotide is the phosphorylated, water-soluble form of vitamin B2. It is a genuine and widely used food colour — a bright yellow that doubles as a nutrient — but in Great Britain it does not carry the number E 106.
The GB list authorises it as E 101(ii) riboflavin-5′-phosphate, sitting alongside E 101(i) riboflavin. E 106 is an older or non-European designation for essentially the same substance, and it survives in product databases that were built from mixed international sources.
Foods commonly containing it
As E 101(ii): breakfast cereals, sauces, desserts and dairy products, some soft drinks, and food supplements. Riboflavin also occurs naturally in milk, eggs, offal, mushrooms and fortified cereals — see vitamin B2 (riboflavin).
Safety summary
The number E 106 does not appear in the FSA Register of Food Additive Authorisations. The substance it describes is authorised, but under a different code: E 101(ii) riboflavin-5′-phosphate, listed in Group II — food colours authorised at quantum satis.
Riboflavin is a water-soluble vitamin. Excess is excreted in the urine, which is why a high dose turns urine bright yellow — a harmless and well-known effect rather than a sign of a problem.
In practice a UK ingredients list will read “riboflavin”, “riboflavin-5′-phosphate” or “E101”. It will not read E 106.