Disodium inosinate explained

Disodium inosinate (E631^[1]) 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.

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,^[2] but the Vegetarian Resource Group reports that all three "leading manufacturers" claim to use fermentation.^[3]

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.^[4] It can also be made by fermentation of sugars such as tapioca starch.^[5]

Some sources claim that industrial levels of production are achieved by extraction from animal products, making E631 non-vegetarian.^[2] 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.^[3] 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.^[6]

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.^[7]

In 2004, disodium inosinate was proposed to be removed from the food additive list by Codex Alimentarius Commission.^[8] This change did not go through: it is still present in the 2009 Codex Alimentarius list.^[9]

Notes and References

1. Web site: Food Standards Australia New Zealand . Food Standards Australia New Zealand . Food Additives- Numerical List . 2 December 2009 . dead . https://web.archive.org/web/20090625024756/http://www.foodstandards.gov.au/newsroom/publications/choosingtherightstuff/foodadditivesnumeric1680.cfm . 25 June 2009.
2. Web site: Vegetarian Society - Fact Sheet - E Numbers - Derived from both plant and animal sources, Animal derived carriers. www.vegsoc.org. 2016-10-09. 7 March 2019. https://web.archive.org/web/20190307174020/https://www.vegsoc.org/sslpage.aspx?pid=728. dead.
   The following source has identical phrasing: Web site: E-numbers : E631 : Sodium inosinate . Food-Info.net . 1998-09-27 . 2013-02-04 .
3. Web site: Yacoubou . Jeanne . Disodium Inosinate and Disodium Guanylate Are All-Vegetable Flavor Enhancers . The Vegetarian Resource Group.
4. Kurihara . K . Umami the Fifth Basic Taste: History of Studies on Receptor Mechanisms and Role as a Food Flavor. . BioMed Research International . 2015 . 2015 . 189402 . 10.1155/2015/189402 . 26247011. 4515277 . free .
5. Conn . Helen . "Umami": The Fifth Basic Taste . Nutrition & Food Science . 1 February 1992 . 92 . 2 . 21–23 . 10.1108/EUM0000000000953.
6. Web site: All PepsiCo India food products and their ingredients are 100% vegetarian . https://web.archive.org/web/20130512201442/http://pepsicoindia.co.in/Download/All%20PepsiCo%20India%20food%20products%20and%20their%20ingredients%20are%20100per%20vegetarian-FAQs.pdf . dead . 12 May 2013 . www.pepsicoindia.co.in.
7. 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
8. Web site: Codex Alimentarius Commission. Codex Alimentarius Commission. [ftp://ftp.fao.org/codex/alinorm04/al04_12e.pdf Report of the 36th Session of the Codex Committee on Food Additives and Contaminants ]. 2 December 2009.
9. Web site: Class Names and the International Numbering System for Food Additives. 7 August 2010 . dead. https://web.archive.org/web/20100905174323/http://www.codexalimentarius.net/web/more_info.jsp?id_sta=7. 5 September 2010.