Metatartaric acid

Metatartaric acid is a food additive. Chemically, it is a polymeric lactone of variable composition and different molecular weights obtained through a dehydration reaction by heating tartaric acid.^[2]

Metatartaric acid

Idealized chemical structure of metartaric acid
Names
Other names E353
Identifiers
CAS Number	39469-81-3 (unspecified form) 56959-20-7 (polyether form)
ChemSpider	32820791
ECHA InfoCard	100.116.846
EC Number	609-694-5
E number	E353 (antioxidants, ...)
PubChem CID	92024228
Properties
Chemical formula	(C4H4O5)n
Molar mass	Variable
Appearance	Off-white solid[1]
Solubility in water	Freely soluble[1]
Solubility in ethanol	Soluble[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Uses

As a food additive, it has the E number E353 and is classified as an acidity regulator.^[1] It is added to wine to prevent the precipitation of potassium hydrogen tartrate and calcium tartrate.^[3]