What Is Disodium Inosinate (E631) In Food: Uses, Safety, Side Effects

Production | Uses | Safety | Side Effects | FAQs

Disodium inosinate (IMP), a kind of nucleotide, also known as disodium 5′-inosinate, is a flavor enhancer with the European food additive number E631. Its purpose in food is to add a meaty or savory flavor, which is called umami taste. IMP is a white granular or powder commonly combined with another flavour enhancer disodium guanylate (GMP) as disodium 5′-ribonucleotides (E635) or with monosodium glutamate (MSG).

How is it made?

It is the disodium salt of inosinic acid that can be produced by two methods: through sugar fermentation OR comes from yeast extract. And the following are the two manufacturing processes.

In the sugar fermentation process, bacterial fermentate carbon source or sugar to get inosine. (1)

Then inosine reacts with phosphoryl chloride to get inosinic acid, finally neutralize to obtain disodium inosinate (2).

Here is the reaction equation: disodium inosinate chemical synthesize

Also, IMP can be made by the degradation of nucleotides into nucleic acid from yeast extract.


Other names IMP, Disodium 5′-inosinate, Disodium inosine-5′-monophosphate, 5′-inosinic acid, disodium salt
CAS number 4691-65-0
Chemical formula C10H11N4Na2O8P
Molecular weight 392.17(anhydrous)
Solubility Soluble in water, 13g/100ml, 20 degree; sparingly soluble in ethanol, practically insoluble in ether.
Stability It is stable at 100 °C and will not decompose until the temperature is around 230 °C.


What are the uses?

Disodium 5′-inosinate is a flavor enhancer that can be used in many processed foods. Its flavor enhancing power is around 50% of disodium guanylate. Commonly used together with MSG or disodium guanylate in seasoning, condiments and salt substitutes for soups, sauces and snack foods but seldom used alone in food. 

With MSG

It is commonly in synergy with monosodium glutamate (MSG) to provide umami taste. For example, it has a significant flavor synergy with MSG at the ratio of 1:7.

With disodium 5’-guanylate

Disodium 5 ribonucleotides is also a taste flavor, known as I+G, a mixture of disodium inosinate and disodium guanylate (E627) at the ratio 1:1. It can be used in MSG-free foods to replace MSG. The strength of flavor-enhancing of the combination of 98% MSG with 2% I+G is around four times that of monosodium glutamate (MSG) alone when. (4)

Is disodium inosinate 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. 


FDA claimed it may be safely used in food as a flavoring adjuvant for human consumption. (5)


Disodium inosinate (E631) is listed in Commission Regulation (EU) No 231/2012 as an authorised food additive and categorized as “additives other than colours and sweeteners” (6)

Safety assessment

EFSA has not previously assessed it as additives to feed or food and the safety cannot be assessed due to not enough information on the production process when in the evaluation in 2014 (7)

It is in the list of remaining food additives to be re-evaluated for the usage level and/or concentration data in food and beverages intended for human consumption, according to Regulation (EU) No 257/2010 (8). However, there is no updated information so far.

UK Food Standards Agency

Categorized in “Others” (9)

Food Standards Australia New Zealand 

In Australia and New Zealand with the code number 631. (10)


Functional class: Food additives: flavor enhancer. (11)

Acceptable daily intake: ADI “not specific” was set in 1993. (12)

What are the Possible Side Effects?

It is common that sometimes consumers have health concerns if disodium inosinate is bad for our health and what are the dangers. It is generally considered safe and has no side effects.

The toxicity study in early years established on rats, rabbits, monkeys, chickens, dogs, and also in humans showed that disodium inosinate did not have significant toxicity, no observed carcinogenicity, genotoxicity, or adverse effects on reproduction. (13)

Pregnant And Breastfeeding

It is generally safe but better consult your doctor.

Frequently asked questions

Is IMP Natural?

Yes, it is natural instead of an artificial flavor. It is widely present in nature as the building blocks of DNA and RNA, such as in meat and seafoods.

Is IMP Vegan?

Yes, as mentioned above, it is vegan as the raw material inosine or inosinic acid and manufacturing process without the use of animal matter or products derived from animal origin. As a food ingredient, it is considered vegan and vegetarians can eat it.

Is IMP Halal?

Yes, it is generally recognised as halal as it is permitted under the Islamic Law and fulfill the conditions of Halal. And we can find some manufacturers certificated with MUI halal.

Is IMP Kosher?

Yes, it is kosher pareve. E631 has met all the “kashruth” requirements and can be certified as kosher. 

Is IMP Gluten free?

Yes, it is gluten free or without gluten as comply with the FDA’s definition of gluten free, that it does not contain wheat, rye, barley, or crossbreeds of these grains.


Now you may have a good knowledge of the flavour enhancer – disodium inosinate (E631), from its production, uses, approved safety, possible side effects and some FAQs such as is it vegan, gluten free, synthetic or natural.

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


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