E631 (Disodium inosinate) is a chemical compound, disodium salt of inosinic acid, purine ribonucleoside monophosphate and is produced by a fermentation process by various bacteria.

The name describes the structure of the molecule:

• Disodium indicates the presence of two sodium atoms in the compound. Sodium is a chemical element that, in this context, is used to form salts with other compounds.
• Inosinate, a salt of inosinic acid. Inosinic acid is a nucleotide, which is a fundamental component of nucleic acids like DNA and RNA.

Industrial Production

• Extraction or Synthesis. Inosinate can be extracted from natural sources or chemically synthesized. The choice between natural extraction and chemical synthesis depends on factors such as cost and availability of raw materials.
• Neutralization. Inosinate is neutralized with sodium to form disodium inosinate. This process enhances the solubility of the compound in water.
• Purification. After neutralization, disodium inosinate is purified to remove impurities and by-products.
• Quality Control and Packaging. The purified disodium inosinate undergoes quality checks to ensure it meets the required standards. After quality control, it is packaged for use as a flavor enhancer in food products.

It appears in the form of a white powder.

What it is used for and where

It has applications in the pharmaceutical, medical and chromatographic sectors.

Food

Ingredient included in the list of European food additives as E631 with the function of flavour enhancer, to improve the taste of food.

Safety

EFSA's Scientific Panel was unable to conclude on the safety of the additive for target species, consumers, users and the environment (1).

Disodium Inosinate studies

• Molecular Formula  C₁₀H₁₁O₈N₄Na₂P·7.5H₂O 
• Molecular Weight    392.171 g/mol
• CAS   4691‐65‐0
• EC number   225‐146‐4

Synonyms:

• Disodium 5'-inosinate
• Sodium inosinate
• Inosinic Acid
• 5′-IMP-Na2
• 5'-Inosinic Acid Disodium Salt
• 5′-Inosinic acid disodium salt hydrate
•  Inosine 5′-monophosphate disodium salt hydrate
• Inosin-5'-monophosphate disodium
• IMP
• I-5′-P
• MDL number MFCD00150372

References____________________________________________________________

(1) EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP); Bampidis V, Azimonti G, Bastos ML, Christensen H, Dusemund B, Fašmon Durjava M, Kouba M, López-Alonso M, López Puente S, Marcon F, Mayo B, Pechová A, Petkova M, Ramos F, Sanz Y, Villa RE, Woutersen R, Anguita M, Brozzi R, Galobart J, Manini P, Tarrés-Call J, Pettenati E. Safety and efficacy of a feed additive consisting of disodium 5'-inosinate (IMP) produced by Corynebacterium stationis KCCM 80235 for all animal species (CJ Europe GmbH). EFSA J. 2022 Mar 7;20(3):e07153. doi: 10.2903/j.efsa.2022.7153.