E635 – Disodium 5'–ribonucleotides - Food additives database

Safety grading ORANGE – SOME CONCERNS

E635 (Disodium 5′-ribonucleotides) is a flavour enhancer used to intensify savoury taste, especially in processed foods where manufacturers want a stronger “umami” profile. From a regulator perspective, the baseline is that these ribonucleotide flavour enhancers are permitted for use and have a long history in the food supply. International evaluations (for example, JECFA (Joint FAO/WHO Expert Committee on Food Additives)) have treated disodium 5′-ribonucleotides as low concern at typical use levels, and EU authorisations allow it within defined food categories and conditions of use.

However, regulatory permission is not the full story for practical consumer guidance. E635 is a mixture of disodium inosinate (E631) and disodium guanylate (E627). These are purine nucleotides, and after ingestion, purines are broken down and ultimately contribute to uric acid formation. For most healthy adults, this metabolism is routine and does not create a meaningful safety issue at realistic additive exposures. The concern is concentrated in specific groups: people with gout, hyperuricemia, impaired kidney function, or those advised to follow a low-purine diet.

Independent nutrition and clinical literature consistently links higher purine exposure and certain dietary patterns to higher serum urate levels and gout risk in susceptible individuals. That evidence does not mean E635 alone causes gout, and it is important not to exaggerate the effect. In most diets, purine intake from whole foods (such as organ meats, some seafood, and certain meat-heavy patterns) is typically much larger than intake from flavour additives. Still, E635 is often found in products that are easy to overconsume (snacks, instant noodles, seasoning mixes), and it can add small incremental purine load across repeated servings.

Net-risk judgement: because credible evidence supports a biological pathway (purine → urate) and because there are identifiable vulnerable groups for whom limiting purines is standard advice, we grade E635 as ORANGE. This is not a “toxic additive” classification. It is a “watch your intake if you are sensitive” classification. For the average consumer, occasional intake is unlikely to be clinically relevant, but for someone managing uric acid, it can be a sensible label to monitor.

Caveats: reactions are not expected to be allergic-type responses, and E635 is not known for genotoxicity or carcinogenicity concerns at permitted use. The practical issue is dietary context and frequency of consumption, especially in people with existing urate-related conditions.

Should You Avoid E635?

If you have gout, hyperuricemia, chronic kidney disease, or you have been told to follow a low-purine diet, it is reasonable to limit foods containing E635, particularly when you consume multiple processed savoury products per day. If you are generally healthy, you do not need to “fear” E635, but you may still choose to reduce it as part of reducing ultra-processed foods overall.

Common Uses

Instant noodles and cup soups (stronger savoury taste with less total seasoning)
Chips, crackers, and savoury snacks (boosted umami flavour)
Seasoning blends, bouillon cubes, and stock powders
Ready meals, sauces, and gravies
Some processed meat and fish products (flavour enhancement)

Common names / Synonyms

Disodium ribonucleotides
Disodium 5′-ribonucleotides
Sodium 5′-ribonucleotides
I+G (inosinate + guanylate)
Disodium inosinate and disodium guanylate mixture

What is it?

E635 is a blend of two nucleotide salts: disodium inosinate (IMP-related) and disodium guanylate (GMP-related). Nucleotides are building blocks of RNA, and in food science these specific nucleotides are well known for their strong umami synergy. On their own, they have flavour activity, but they become much more potent when combined with glutamates such as MSG. This synergy is why E635 is widely used: it can produce a “meatier” taste perception without requiring large amounts of flavouring ingredients.

From a manufacturing standpoint, modern production usually relies on controlled microbial fermentation and downstream purification. Producers typically use carbohydrate feedstocks and selected microorganisms to generate nucleotide intermediates, followed by extraction, purification, and conversion to the disodium salt forms. Another industrial route can involve hydrolysis of RNA-rich materials (for example, yeast-derived sources) and subsequent purification steps. The final additive is a crystalline powder that dissolves readily in water, making it convenient for dry seasoning blends and liquid formulations.

In practical labeling, E635 is most often seen in heavily seasoned, savoury products. Because it is used at relatively low concentrations, consumers may not notice it as a “dominant” ingredient, but it can significantly influence perceived flavour intensity. This also matters nutritionally: E635 is often a marker that a product is engineered for strong palatability, which can encourage overconsumption of snack-type foods. That broader dietary context is one reason ORANGE is a more honest grade than GREEN for consumer guidance.

Where it’s allowed (EU vs US)

In the EU, E635 is authorised as a food additive with defined conditions of use in the European Commission’s food additives database. In the US, its component nucleotides are permitted for flavour use under applicable FDA regulations and listings, and they are widely used in processed foods under good manufacturing practice.

E635 – Disodium 5’–ribonucleotides