Flavour enhancers are food additives that are added to food to enhance its flavour and/or odour, to increase the perception of a single flavour, or to increase the overall perception of all its flavour characteristics. However, flavour enhancers do not impart any flavour or odour to food.[3][5]
Like other food additives, they are identified by their name and/or a code number, the E numbering system, where E stands for Europe, and are numbered from E620 to E650.[6]
Almost all flavour enhancers authorized for use in the European Union belong to three groups or classes: glutamates, inositates and guanylates. Among these, the three most commonly used molecules are monosodium glutamate (E621), disodium inosinate (E631) and disodium guanylate (E627).
Based on the currently available scientific evidence, flavour enhancers, when used in compliance with established guidelines, do not pose a risk to human health.[1][4]
Contents
Glutamates
Glutamates include glutamic acid (E620), one of the amino acids that make up proteins, and its sodium, potassium, calcium, and ammonium salts. They are molecules that increase umami taste in food, which is the fifth basic flavor that humans can perceive, in addition to salty, sweet, bitter, sour, and which is similar to the taste of meat broth.[2][9]
They are numbered from E620 to E625.
Monosodium glutamate or sodium salt of glutamic acid was the first flavor enhancer to be used industrially, and, among glutamates, it is the most widely used. It is added to foods, such as soups, salty snacks and sauces, to induce the umami taste.[5][8] It is also named sodium glutamate, glutamic acid monohydrate, vetsin, ajinomoto and monosodium L-glutamate on the label’s ingredient list.
Inosinates
Inosinates, namely, inosine monophosphate or inosinic acid (E630), one of the nucleotides used to make DNA and RNA, and its sodium, potassium and calcium salts, are flavour enhancers that enhance the umami flavour.[2][9]
They are about 10 times more powerful than glutamates and are numbered from E630 to E633.
Among inosinates, the most widely used is disodium inosinate, which is often added to foods in conjunction with disodium guanylate, a mixture known as disodium 5′-ribonucleotides (E635).
Guanylates
Guanylates, namely guanosine monophosphate or guanylic acid (E626), one of the nucleotides used to make RNA and DNA, and its calcium, potassium and sodium salts, are flavour enhancers that do not have the umami taste, but are capable of strongly enhancing many other flavours.[2][9]
They are numbered from E626 to E629.
Disodium guanylate is the most widely used guanylate. Since it is expensive, it is generally used in combination with monosodium glutamate or disodium inosinate.
Examples of flavour enhancers
Below is a review of the flavour enhancers included in the list of food additives approved in the European Community according to Regulation 1129/2011 of the European Commission, published on November 11, 2011. This list is an amendment of Annex II to Regulation (EC) No. 1333/2008 of the European Parliament, and was in turn amended in 2013.[3]
| E-number | Additive/Class | |
| Glutamates | ||
| E620 | Glutamic acid | |
| E621 | Monosodium glutamate | |
| E622 | Monopotassium glutamate | |
| E623 | Calcium diglutamate | |
| E624 | Monoammonium glutamate | |
| E625 | Magnesium diglutamate | |
| Guanylates | ||
| E626 | Guanylic acid | |
| E627 | Disodium guanylate | |
| E628 | Dipotassium guanylate | |
| E629 | Calcium guanylate | |
| Inosinates | ||
| E630 | Inosinic acid | |
| E631 | Disodium inosinate | |
| E632 | Dipotassium inosinate | |
| E633 | Calcium inosinate | |
| Other compounds | ||
| E634 | Calcium 5′-ribonucleotides | |
| E635 | Disodium 5′-ribonucleotides | |
| E640 | Glycine and its sodium salt | |
| E650 | Zinc acetate | |
Health effects
For a long time, monosodium glutamate has been thought to cause allergic reactions and intolerances, such as the “Chinese restaurant syndrome.” However, the scientific community, based on numerous studies, has established that this flavour enhancer, in the authorized amounts, is safe for consumers, including children.[1][7]
Although the purine moiety of inosinates and guanylate is metabolized to uric acid, which is involved in the genesis of gout, the amount ingested is negligible compared to that present in foods. Therefore, their contribution to gout development appear to be completely negligible. More generally, regarding the effects on health, no evidence of adverse effects on reproduction, carcinogenicity, or teratogenicity has been found.[4]
It can therefore be concluded that flavour enhancers, when used according to specific guidelines, are not harmful to health.
References
- ^ a b Bera T.K., Kar S.K., Yadav P.K., Mukherjee P., Yadav S. and Joshi B. Effects of monosodium glutamate on human health: a systematic review. World J Pharm Sci 2017;139-144.
- ^ a b c Briand L. and Salles C. 4 – Taste perception and integration. Editor: Etievant P., Guichard E., Salles C. and Voilley A. Booktitle: Flavor. Woodhead Publishing. 2016;101-119. doi:10.1016/B978-0-08-100295-7.00004-9
- ^ a b Commission Regulation (EU) No 1129/2011 of 11 November 2011 amending Annex II to Regulation (EC) No 1333/2008 of the European Parliament and of the Council by establishing a Union list of food additives. https://eur-lex.europa.eu/eli/reg/2011/1129/2013-11-21
- ^ a b Ekelman K. and Raffaele K.C. Disodium 5′-guanylate and disodium 5′-inosinate. Additives evaluation branch, division of health effects evaluation. Center for food safety and applied nutrition. Food and Drug Administration, Washington, DC, USA.
- ^ a b European Union. Guidance notes on the classification of a flavouring substance with modifying properties and a flavour enhancer. 27 May 2014. https://food.ec.europa.eu/system/files/2016-10/fs_food-improvement-agents_flavourings-guidance_modifying_properties.pdf
- ^ Food Standards Agency. Approved additives and E Numbers. Last updated: 23 January 2024.
- ^ Geha R.S., Beiser A., Ren C., Patterson R., Greenberger P.A., Grammer L.C., Ditto A.M., Harris K.E., Shaughnessy M.A., Yarnold P.R., Corren J., Saxon A. Multicenter, double-blind, placebo-controlled, multiple-challenge evaluation of reported reactions to monosodium glutamate. J Allergy Clin Immunol 2000;106(5):973-80. doi:10.1067/mai.2000.110794
- ^ Moldovan O.L., Rusu A., Tanase C., Vari C.E. Glutamate – A multifaceted molecule: Endogenous neurotransmitter, controversial food additive, design compound for anti-cancer drugs. A critical appraisal. Food Chem Toxicol 2021;153:112290. doi:10.1016/j.fct.2021.112290
- ^ a b c Nelson D.L., Cox M.M. Lehninger. Principles of biochemistry. 6th Edition. W.H. Freeman and Company, 2012