Disodium inosinate

Disodium inosinate (E631^[2]) is the disodium salt of inosinic acid with the chemical formula C₁₀H₁₁N₄Na₂O₈P. It is used as a food additive and often found in instant noodles, potato chips, and a variety of other snacks.

Disodium inosinate

Names
IUPAC name Disodium 5′-inosinate
Systematic IUPAC name Disodium [(2R,3S,4R,5R)-3,4-dihydroxy-5-(4-oxo-2,3-dihydro-9H-purin-9-yl)oxolan-2-yl]methyl phosphate[1]
Other names Sodium 5′-inosinate Disodium inosin 5′-monophosphate Inosine 5′-(disodium phosphate) Sodium inosinate
Identifiers
CAS Number	4691-65-0  Y Y
3D model (JSmol)	Interactive image Interactive image
ChemSpider	19594 Y
ECHA InfoCard	100.022.860
E number	E631 (flavour enhancer)
PubChem CID	20819
UNII	T2ZYA7KC05 Y
CompTox Dashboard (EPA)	DTXSID4044242
InChI InChI=1S/C10H13N4O8P.2Na/c15-6-4(1-21-23(18,19)20)22-10(7(6)16)14-3-13-5-8(14)11-2-12-9(5)17;;/h2-4,6-7,10,15-16H,1H2,(H,11,12,17)(H2,18,19,20);;/q;2*+1/p-2/t4-,6-,7-,10-;;/m1../s1 Y Key: AANLCWYVVNBGEE-IDIVVRGQSA-L Y InChI=1/C10H13N4O8P.2Na/c15-6-4(1-21-23(18,19)20)22-10(7(6)16)14-3-13-5-8(14)11-2-12-9(5)17;;/h2-4,6-7,10,15-16H,1H2,(H,11,12,17)(H2,18,19,20);;/q;2*+1/p-2/t4-,6-,7-,10-;;/m1../s1 Key: AANLCWYVVNBGEE-IMCBXCBXBI
SMILES C1=NC(=O)C2=C(N1)N(C=N2)C3C(C(C(O3)COP(=O)([O-])[O-])O)O.[Na+].[Na+] [Na+].[Na+].[O-]P([O-])(=O)OC[C@H]3O[C@@H](n1cnc2c1N\C=N/C2=O)[C@H](O)[C@@H]3O
Properties
Chemical formula	C10H11N4Na2O8P
Molar mass	392.171 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Commercial disodium inosinate may either be obtained from bacterial fermentation of sugars or prepared from animal products. The Vegetarian Society reports that production from meat or fish is more widespread,^[3] but the Vegetarian Resource Group reports that all three "leading manufacturers" claim to use fermentation.^[4]

Use as a food additive

Disodium inosinate is used as a flavor enhancer, in synergy with monosodium glutamate (MSG) to provide the umami taste. It is often added to foods in conjunction with disodium guanylate; the combination is known as disodium 5′-ribonucleotides.

As a relatively expensive product, disodium inosinate is usually not used independently of glutamic acid; if disodium inosinate is present in a list of ingredients, but MSG does not appear to be, it is possible that glutamic acid is provided as part of another ingredient or is naturally occurring in another ingredient like tomatoes, Parmesan cheese, or yeast extract.

Origin

Inosinate is naturally found in meat and fish at levels of 80–800 mg/100 g.^[5] It can also be made by fermentation of sugars such as tapioca starch.^[6]

Some sources claim that industrial levels of production are achieved by extraction from animal products, making E631 non-vegetarian.^[3] However, an interview by the Vegetarian Resource Group reports that all three "leading manufacturers" (one being Ajinomoto) claims to use an all-vegetarian fermentation process.^[4] Producers are generally open to providing information on the origin. E631 is in some cases labeled as "vegetarian" in ingredients lists when produced from plant sources.^[7]

Toxicology and safety

In the United States, consumption of added 5′-ribonucleotides averages 4 mg per day, compared to 2 g per day of naturally occurring purines. A review of literature by an FDA committee found no evidence of carcinogenicity, teratogenicity, or adverse effects on reproduction.^[8]

In 2004, disodium inosinate was proposed to be removed from the food additive list by Codex Alimentarius Commission.^[9] This change did not go through: it is still present in the 2009 Codex Alimentarius list.^[10]

See also

• Acceptable daily intake
• Disodium guanylate
• Guanosine monophosphate
• Glutamate flavoring
• Kikunae Ikeda
• Umami
• Ajinomoto
• Tien Chu Ve-Tsin
• Glutamic acid
• Disodium glutamate
• Monopotassium glutamate
• Inosinic acid
• Adenosine monophosphate
• Hypoxanthine-guanine phosphoribosyltransferase
• Ribonucleoside

References

1. CID 20819 from PubChem
2. Food Standards Australia New Zealand. "Food Additives- Numerical List". Archived from the original on 25 June 2009. Retrieved 2 December 2009.
3. "Vegetarian Society - Fact Sheet - E Numbers - Derived from both plant and animal sources, Animal derived carriers". www.vegsoc.org. Archived from the original on 7 March 2019. Retrieved 9 October 2016.
   The following source has identical phrasing: "E-numbers : E631 : Sodium inosinate". Food-Info.net. 27 September 1998. Retrieved 4 February 2013.
4. Yacoubou, Jeanne. "Disodium Inosinate and Disodium Guanylate Are All-Vegetable Flavor Enhancers". The Vegetarian Resource Group.
5. Kurihara, K (2015). "Umami the Fifth Basic Taste: History of Studies on Receptor Mechanisms and Role as a Food Flavor". BioMed Research International. 2015: 189402. doi:10.1155/2015/189402. PMC 4515277. PMID 26247011.
6. Conn, Helen (1 February 1992). ""Umami": The Fifth Basic Taste". Nutrition & Food Science. 92 (2): 21–23. doi:10.1108/EUM0000000000953.
7. "All PepsiCo India food products and their ingredients are 100% vegetarian" (PDF). www.pepsicoindia.co.in. Archived from the original (PDF) on 12 May 2013.
8. Disodium 5′-guanylate and Disodium 5′-inosinate, K. Ekelman and K. C. Raffaele, Additives Evaluation Branch, Division of Health Effects Evaluation, Center for Food Safety and Applied Nutrition, Food and Drug Administration, Washington, DC, USA and other
9. Codex Alimentarius Commission. "Report of the 36th Session of the Codex Committee on Food Additives and Contaminants" (PDF). Retrieved 2 December 2009.^{[permanent dead link]}
10. "Class Names and the International Numbering System for Food Additives". Archived from the original on 5 September 2010. Retrieved 7 August 2010.