|Jmol-3D images||Image 1
|Molar mass||134.09 g mol−1|
16-18 °C, 289-291 K, 61-64 °F
172 °C, 445 K, 342 °F
|Viscosity||2.1 Pa·s (20 °C)|
|R-phrases||R22 R23 R34|
|S-phrases||S7/9 S26 S36/37/39 S45|
| (what is: / ?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Dimethyl dicarbonate (DMDC) is a colorless liquid with a sharp odor. Its primary use is as a beverage preservative and or processing aid or sterilant (INS No. 242), and acts by inhibiting the enzymes acetate kinase and L-glutamic acid decarboxylase. It has also been proposed that methoxycarbonylation of the histidine part of the enzymes alcohol dehydrogenase and glyceraldehyde 3-phosphate dehydrogenase by DMDC inhibits these essential enzymes also. Once it has been added to beverages, the efficacy of the chemical is provided by the following reactions:
- DMDC + H2O → 2 CH3OH + 2 CO2
- DMDC + Ethanol → Ethyl methyl carbonate
- DMDC + NH3 → Methyl carbamate
- DMDC + Amino acid → Derived carboxymethyl
DMDC is sometimes used as a preservative in wine as a replacement to sulfur dioxide, inactivating wine spoilage yeasts such as Brettanomyces. In the U.S., the FDA approved its use in wines in 1988, with the maximum level being permitted set at 200 mg/L, and only if there were fewer than 500 yeast cells/mL at time of dosage. It is also approved in the EU, where it is listed under E number E242, and Australia  but not New Zealand.
The application of DMDC is particularly useful when wine needs to be sterilized but cannot be sterile filtered, pasteurized, or sulfured. DMDC is used to stabilize non-alcoholic beverages such as carbonated or non-carbonated juice beverages, isotonic sports beverages, iced teas and flavored waters.
The EU Scientific Committee on food, the FDA in the United States and the JECFA of the WHO have confirmed the safe use in beverages.
- [dead link]
- DMDC's role in bottle stability - dimethyl dicarbonate, Wines & Vines, Oct 1990
- US Food and Drug Administration: "Listing of Food Additives Status Part I". Retrieved 2011-10-27.
- UK Food Standards Agency: "Current EU approved additives and their E Numbers". Retrieved 2011-10-27.
- Australia New Zealand Food Standards Code"Standard 4.5.1 - Wine Production Requirements (Australia Only)". Retrieved 2012-05-02.