What Is Disodium 5′-ribonucleotides (E635) In Food? Uses, Safety, Side Effects

What is it |Production | Uses | Safety | Side Effects 

Disodium 5′-ribonucleotides, also known as I+G, is a flavor enhancer made of disodium inosinate (E631) and disodium guanylate (E627) with the ratio 1:1. The European food additive number for it is E635. It can be used in synergy with MSG (E621) to provide umami taste or as a replacement for MSG.

What is disodium 5′-ribonucleotides?


Disodium 5′-ribonucleotide is a mixture of nucleotides disodium guanylate and disodium inosinate, in the proportion of 50% each.

How is it made?

Both E631 and E627 can be produced from yeast extract or from the fermentation of carbohydrate and then through reaction with sodium hydroxide.


Other Names

  • I+G
  • Sodium ribonucleotides
  • Disodium inosinate and guanylate

CAS Number


Chemical formula

  • C10H11N4O8P · nH2O
  • C10H12N5Na2O8P · nH2O

Molecular Weight



Disodium 5′-ribonucleotides chemical structure




An odourless, white powder or granular. 


Easy to absorb water in the air, around 20-30% of water.


  1. In Water: soluble in water, 25g in 100ml water in 20 degree.
  2. In Organic Solvents: sparingly soluble in ethanol, practically insoluble in ether.

What are the uses?

I+G is a natural, vegan, and gluten free ingredient that can be used as a flavor enhancer to substitute monosodium glutamate (MSG) in MSG free food. It can also be used with MSG at the usage level around 2-10% of MSG to provide a synergistic enhancement of umami taste in sauces, seasonings and condiments. 

The following are the common food uses of I+G and the added levels recommended by the manufacturer, Ajinomoto (1): 

  • Meat products: ≥ 0.01%
  • Broths: 0.50 – 1.00%
  • Soups: 0.20 – 0.30%
  • Spices (10% salt or higher): 0.25-2.8%
  • Snacks:0.02 – 0.03%
  • Tomato sauce: 0.02 – 0.04%
  • Mustard: 0.02 – 0.04%
  • Salad dressings: 0.01 – 0.02%
  • Vegetable preserves, fish byproducts, frozen food, biscuits, pasta / dough: 0.01%

Is disodium 5′-ribonucleotides safe?

Yes, its safety when used as a food additive has been approved by the U.S. Food and Drug Administration (FDA), European Food Safety Authority (EFSA),  Joint FAO/WHO Expert Committee on Food Additives (JECFA), as well as other authorities.


We can see FDA approved disodium guanylate and disodium inosinate as a direct food additive that may be safely used as a flavor enhancer in foods. However, cannot find such information of I+G.


Disodium 5′-ribonucleotides (E635) is listed in Commission Regulation (EU) No 231/2012 as an authorised food additive and categorized as “additives other than colours and sweeteners” (2)

Its usage level in food and beverages for human consumption needs to be re-evaluated together with IMP and GMP, which was requested since Oct, 2018. (3)

UK Food Standards Agency

Categorized in “Others” (4)

Food Standards Australia New Zealand 

It is an approved ingredient in Australia and New Zealand with the code number 635. (5)


Functional class: Food additives: flavor enhancer. (6)

Acceptable daily intake: ADI “not specific” was set in 1974. (7)

What are the Possible Side Effects

It is common that sometimes consumers have health concerns if disodium 5′-ribonucleotides is bad for our health and what are the dangers. Like with disodium guanylate and disodium inosinate, it is generally considered safe and almost has no reported side effects. (8).


Now you may have a good knowledge of the flavour enhancerdisodium 5′-ribonucleotides (E635), from its production, uses, approved safety, possible side effects.

What kinds of food packaging have you found this ingredient in? Let me know in the comments.


  1. Mayank Kulkarni
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