Disodium ribonucleotides

Disodium ribonucleotides is a blend of disodium guanylate (E627) and disodium inosinate (E631), used together for synergistic umami flavour enhancement. When combined with monosodium glutamate (E621), these nucleotides produce a much stronger umami sensation than any single component alone, allowing manufacturers to use lower total quantities of glutamate. E635 is common in instant noodles, snack seasonings, crisps, and ready-made soups.

JECFA evaluated disodium ribonucleotides in 1987 and did not establish a numerical ADI, indicating no safety concern at typical food-use levels. However, ribonucleotides are metabolised in the body to purines, which break down to uric acid. In individuals with gout or hyperuricaemia, elevated purine intake — including from E635 — can trigger flares by raising uric acid concentrations.

E635 is approved globally, including in the EU, the United States, Japan, and Korea. For the general healthy population it presents no concern. Its presence in processed snack foods is worth noting for anyone managing gout, uric acid kidney stones, or conditions requiring a low-purine diet. Looksee assigns a limit rating because of this specific population concern, not due to any toxicological risk for healthy consumers.