Disodium 5-ribonucleotides
Disodium 5-ribonucleotides (E635) is a roughly equal blend of disodium guanylate (E627) and disodium inosinate (E631), used with MSG to boost savoury flavour. Because it contains inosinate, the same question applies: the source may be fermentation or fish, and the label will not say.
Disodium 5-ribonucleotides is not a single substance but a blend, conventionally about 50:50 guanylate and inosinate, sold to manufacturers as "I+G". It is used at very low levels because its synergy with glutamates is strong: a little allows less MSG and less salt for the same savoury intensity.
Its source inherits the ambiguity of its inosinate half — fermentation of plant starch, or extraction from fish or meat — and EU labelling does not require the source to be declared. EFSA set a group acceptable daily intake for E626–E635 in 2021.
On the label
- E-number
- E635
- INS number
- INS 635
- Functional class
- Flavour enhancer
- Also known as
- Flavour enhancer 635 · INS 635 · Ribotide · I+G
Frequently asked questions
It depends on the source. It is a blend of the guanylate and inosinate salts, made either by fermentation or from fish or meat. Because it contains inosinate, the same fish-or-fermentation ambiguity applies and the label will not resolve it. The same applies to a vegetarian diet.
Yes — the additive itself contains no gluten. A gluten-free claim belongs to the finished product, though — check the pack, not the additive.
It is a blend of the guanylate and inosinate salts, made either by fermentation or from fish or meat, and EU labelling does not require the source to be declared — so the E-number alone cannot answer this. A halal certification mark on the finished product, or the manufacturer directly, is the only reliable signal.
EFSA re-evaluated the ribonucleotides in 2021 and set a group acceptable daily intake covering E626–E635. As purines they metabolise to uric acid, which is why gout guidance sometimes mentions them, though the quantities used are small.