E635 - Disodium 5'-ribonucleotide

At a glance

• What it is: A flavor enhancer made from ribonucleotides (building blocks of RNA) in their disodium salt form.
• What it does: Lifts savory/umami taste and rounds out flavors, often used alongside glutamates.
• Where it’s found: Savory snacks, instant noodles, soups, sauces, bouillons, and some processed meats.
• Composition: Usually a blend of disodium inosinate and disodium guanylate.
• Regulatory status: Authorized in the EU with defined purity specifications; use levels are set by category-specific rules. ¹

Why is Disodium 5'-ribonucleotide added to food?

Manufacturers add E635 to make foods taste more savory and “full.” It enhances umami—the taste found naturally in foods like tomatoes, mushrooms, aged cheese, and meats. E635 is commonly paired with monosodium glutamate (MSG) or naturally occurring glutamates to create a richer flavor profile.

Chemically, E635 is a mixture of the disodium salts of 5'-inosinic acid (IMP) and 5'-guanylic acid (GMP), both of which are nucleotides found in living cells and associated with savory taste. ²

What foods contain Disodium 5'-ribonucleotide?

You’re most likely to find E635 in:

• Savory snacks (chips/crisps, flavored crackers)
• Instant noodles and seasoning packets
• Dry soup mixes and canned/instant soups
• Bouillon cubes and stock concentrates
• Sauces, gravies, and marinades
• Some processed meats and meat analogues

International food standards list E635 as a flavor enhancer that may be used, where permitted, across many savory food categories. ³

What can replace Disodium 5'-ribonucleotide?

• Glutamate-based options: monosodium glutamate or glutamic acid
• Single nucleotides: disodium inosinate or disodium guanylate
• Ingredient-based umami: yeast extract, tomato paste, mushroom powder, seaweed, long-simmered stocks

The best substitute depends on the recipe, flavor target, and labeling goals.

How is Disodium 5'-ribonucleotide made?

There are two main routes described in official specifications:

• Fermentation: Microorganisms produce the nucleotides from carbohydrate sources; the products are then purified and neutralized with sodium.
• Enzymatic hydrolysis: RNA (ribonucleic acid), often from yeast, is broken down by enzymes to 5'-ribonucleotides, which are converted to their disodium salts. ²

Is Disodium 5'-ribonucleotide safe to eat?

In the European Union, E635 is an authorized food additive with defined identity and purity criteria in law. Its use must follow category-specific rules and the general principle of using only as much as needed to achieve the intended effect. ¹ International food standards also recognize it as a flavor enhancer. ³

As with all additives, manufacturers are expected to use the lowest effective amount to meet technological need. Consumers who wish to avoid it can check ingredient lists for “disodium 5'-ribonucleotides,” “E635,” “I+G,” or the names of its components.

Does Disodium 5'-ribonucleotide have any benefits?

• Flavor impact at low levels: E635 delivers a strong savory boost in tiny amounts, which helps round out flavors in complex foods.
• Potential for salt reduction strategies: Umami enhancers are sometimes used in reformulation to keep foods tasty while reducing added sodium, as encouraged in voluntary sodium-reduction efforts. ⁴

Who should avoid Disodium 5'-ribonucleotide?

E635 is made of purine nucleotides (IMP and GMP). People with gout or hyperuricemia, who are often advised to limit high-purine sources to manage uric acid levels, may prefer to limit concentrated nucleotide additives like E635. ⁴ If you’ve been told to follow a low-purine diet, discuss label reading and ingredient choices with your healthcare professional.

Individuals who avoid glutamate-containing ingredients should know E635 is often used together with MSG; checking labels can help you steer clear if desired.

Myths & facts

• “It’s the same as MSG.” False. E635 is a mixture of nucleotides (IMP and GMP), not glutamate. That said, it’s often used with MSG in savory foods.
• “It’s only artificial.” Not exactly. The nucleotides themselves occur naturally in cells; for food use, they are produced by fermentation or by enzymatically breaking down RNA, then purified.
• “It hides poor-quality ingredients.” Flavor enhancers can round out taste, but they don’t replace good formulation. Regulations also require honest labeling.

Disodium 5'-ribonucleotide in branded foods

On ingredient lists, look for “disodium 5'-ribonucleotides,” “E635,” or “I+G.” You’ll most often see it on savory snack flavors, noodle seasoning sachets, soup mixes, bouillon or stock bases, and some sauces. Stores may carry both versions of similar products—with and without E635—so comparing labels can help you choose what fits your preferences.

References

Footnotes

1. Regulation (EC) No 1333/2008 on food additives — European Union. https://eur-lex.europa.eu/eli/reg/2008/1333/oj ↩ ↩²

2. Commission Regulation (EU) No 231/2012 laying down specifications for food additives listed in Annexes II and III to Regulation (EC) No 1333/2008 — European Union. https://eur-lex.europa.eu/eli/reg/2012/231/oj ↩ ↩²

3. General Standard for Food Additives (GSFA) — Codex Alimentarius. https://www.fao.org/gsfaonline ↩ ↩²

4. Gout — National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH. https://www.niddk.nih.gov/health-information/kidney-disease/gout ↩ ↩²