Sequestrants in food

A sequestrant is a substance that forms chemical complexes with metal ions.

Vietnam regulates additives through a list of permitted additives (Circular 24/2019/TT-BYT, referencing international Codex standards); a substance not on the list is not permitted in Vietnam, and that is the first tier of the Yenzo Scale — see how levels are set.

Sequestrants: moderate risk

Moderate risk: moderate concern. How we score →

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E539Sodium thiosulphate

Sequestrants: low risk

Low risk: limited concern or ongoing debate. How we score →

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E338Phosphoric acid E339Sodium phosphates E340Potassium phosphates E385Calcium disodium EDTA E386Disodium EDTA E450Diphosphates E451Triphosphates E452Polyphosphates E472Esters of mono- and diglycerides of fatty acids

Sequestrants: very low risk

Very low risk: no concern at the levels used in food. How we score →

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E262Sodium acetates E296Malic acid E300Ascorbic acid E330Citric acid E331Sodium citrates E332Potassium citrates E333Calcium citrates E334Tartaric acid (L(+)-)E335Sodium tartrates E337Sodium potassium tartrate E3701,4-Heptonolactone E400Alginic acid E401Sodium alginate E516Calcium sulphate E575Glucono-delta-lactone E576Sodium gluconate E577Potassium gluconate E578Calcium gluconate E1505Triethyl citrate

Fun fact. EDTA (ethylenediaminetetraacetic acid) is synthesized on an industrial scale from ethylenediamine, formaldehyde and a source of cyanide (HCN or NaCN). According to the source page, written in 2004, over 100,000 metric tons are produced worldwide each year. The unusual property of EDTA is its ability to chelate, or complex, metal ions in 1:1 metal-to-EDTA complexes. Because of this strong complexing ability for most metal ions, it is used in the food industry as a sequestering agent. Complexing the metal ion may prevent further reactions, such as binding metals that are cofactors for enzymes, or remove a metallic taste, such as metal contamination added during processing. The pioneering work with EDTA was done by Gerold Schwarzenbach in the 1940s. Source: EDTA – A Molecule with a Complex Story (Molecule of the Month, March 2004, University of Bristol)

Frequently asked questions about sequestrants

Which foods contain sequestrants?

Sequestrants appear in foods where a maker needs to bind the metal ions in the product. According to Yenzo pages, E330 (citric acid) is common in soft drinks, juices, sweets, jelly, jams and sauces, and E331 in soft drinks, processed cheese, milk and sweets. Each code has its own page listing the products where it is usually found.

How can I recognise sequestrants on a label?

Labels usually write the group name followed by the INS number in brackets, for example “sequestrant (330)”, or the code E330, or the name of the substance (citric acid). A substance may be written in any of these ways.

Which sequestrants are the most common?

Yenzo does not rank additives. Some codes of this group that have a page on Yenzo: E330 (citric acid), E331 (sodium citrates), E385 (calcium disodium EDTA), E386 (disodium EDTA), E450 (diphosphates). All of them are named in Appendix 1 of Circular 24/2019/TT-BYT.

Other categories

Updated 28 October 2026

How Yenzo scores

Sources (1)

EDTA – A Molecule with a Complex Story (Molecule of the Month, March 2004, University of Bristol)

Information only, not medical advice. The risk level is the additive's class in Yenzo's open scoring method, based on the cited source.