E635 Flavour enhancer

Disodium 5'-Ribonucleotides

Written by the VitaWhat editorial team · Medically reviewed by Steve Davis · Last reviewed 24 July 2026 · Editorial policy

What it does

Powerful umami enhancer (with MSG).

How it's made

Made from yeast/fish; blend of guanylate and inosinate.

Disodium 5'-ribonucleotides is a ready-made blend of the two nucleotide flavour enhancers, disodium guanylate and disodium inosinate, supplied together in one ingredient. It is used to boost savoury umami taste and is especially potent alongside glutamate (MSG).

It is produced by combining the two nucleotides, each made by fermentation and enzyme processing: microbes generate nucleic acids or the individual building blocks, enzymes release the guanylate and inosinate, and these are neutralised with sodium and blended in roughly equal proportions.

The mixed nucleotide salts are purified and crystallised into a white powder. Selling the two together is convenient because they are almost always used as a pair, and the blend provides a strong, rounded savoury enhancement in snacks, seasonings, instant noodles and sauces when combined with glutamate.

Possible reactions

Purine content — caution with gout; not always vegetarian.

Sources & references

  1. UK Food Standards Agency — Food additives
  2. EFSA — Food additives

Related entries

Disodium GuanylateDisodium InosinateGlutamic AcidMonopotassium GlutamateMonosodium Glutamate (MSG)Acacia (Gum Arabic)
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