Description
Dimethyl dicarbonate (DMDC), also known as Viguolin, is a kind of fruit juice beverage preservative (INS No. 242) that is allowed to be used in my country's food additive use standards. Under normal or even low temperature conditions, DMDC has a strong ability to kill many contaminating bacteria in fruit juice drinks, and its antiseptic effect is closely related to the modification and inactivation of key enzyme proteins in the bacteria by DMDC. Compared with other physical sterilization technologies, the use of DMDC is low in cost, simple and safe to operate, and does not affect the taste, smell and color of the product. It has become one of the hotspots in the research of emerging non-thermal sterilization technologies.
Mechanism of action
Dimethyl dicarbonate has been approved by FDA for use as a yeast inhibitor in bottled wines ( FR Oct. 21 , 1988 ) .It is highly reactive and can react chemically with a variety of reactive groups (such as sulfhydryl, hydroxyl, amino and carboxyl). Among them, the researchers focused on the characteristics of the reaction between pyrocarbonate compounds and enzyme proteins. The results show that in the reaction between enzyme protein and pyrocarbonate compounds, the imidazole group in histidine residues in the enzyme protein is mainly involved in the reaction to form methyl (or ethyl) oxyformyl imidazole group. In addition, studies have also found that many enzymes (such as bovine brain tissue succinate semialdehyde reductase, nucleic acid hydrolase, alcohol dehydrogenase, etc.) have been modified by pyrocarbonate compounds, their enzyme activity has been significantly reduced, and the enzyme activity has decreased and the enzyme activity has decreased. The degree of histidine modification in the protein has a significant correlation.
Uses
Dimethyl dicarbonate (DMDC), a chemical used to combat brettanomyces in wine, is classified as an additive.DMDC is allowed for the preservation of nonalcoholic flavored drinks, alcohol-free wine, and liquid-tea concentrate in ingoing amounts up to 250 mg/L.Because of its reactivity to nucleophilic groups present in proteins, it easily binds to these, which, in the case of enzymes, leads to inactivation of these and hence to inactivation of microorganisms.150In an aqueous medium, it undergoes complete hydrolysis to methanol and carbon dioxide within a few hours. The EC Directive provides a remark that dimethyl dicarbonate residues are not detectable in drinks.
Preparation
In a 2000ml reaction flask, add 400g methyl chloroformate (industrial grade), 400ml dichloromethane, add 143.82g dodecyldimethylbenzylammonium chloride, stir and cool to 5-15°C, Add 1166gl 4% sodium hydroxide aqueous solution dropwise. After the addition is complete, let stand for layering. Discard the water layer. Add 32g 85% sulfuric acid to the organic layer. Stir for 1.5 hours at room temperature. Separate the layers. Add anhydrous magnesium sulfate to dry the organic layer and filter. , Then vacuum distillation, first remove the solvent, and then collect the 200Pa, 30°C -35°C distillate to obtain 232g of colorless liquid product dimethyl dicarbonate, yield 81.9%, freezing point 17°C, GC purity 99.9%.
Safety Profile
Dimethyl dicarbonate (Velcorinor DMDC) is now used as a preservative in many countries but its toxicity requires the use of special dispensing equipment. Dimethyl dicarbonate decom-poses to CHgOH and CO2 in a product and its maximum rate of addition is typi-cally 0.025 wt%.
DMDC is used in the beverage industry for supplemental microbial control in beverages during the final stages of filling. It is added to beverages, whose viable microorganism load was previously reduced by other technologies, immediately prior to bottling, canning, or other forms of final packaging. To ensure its safe use, the agency set the maximum amount of DMDC that may be added to food at 250 parts per million (ppm). DMDC is currently approved under § 172.133(b)(1) and (b)(2) as an inhibitor of yeast in various beverages under normal circumstances of bottling or canning where the viable yeast count has been reduced to 500 per milliliter (mL) or less by current good manufacturing practices. DMDC is also approved under § 172.133(b)(3) and (b)(4) as an inhibitor of yeast in additional beverages. During its review of the subject petition, FDA found that restrictions given in paragraphs (b)(1) and (b)(2) were inadvertently omitted from paragraphs (b)(3) and (b)(4).
https://www.federalregister.gov/documents/2001/03/07/01-5511/food-additives-permitted-for-direct-addition-to-food-for-human-consumption-dimethyl-dicarbonate
Chemical Properties
Dimethyl dicarbonate (DMDC) is a colourless liquid with a slightly pungent aroma. It is primarily used as a beverage preservative, processing aid, or sterilant (Enumber 242). The application of DMDC is particularly useful when wine needs to be sterilized but cannot be sterile filtered, pasteurized, or sulfured. DMDC is also used to stabilize non-alcoholic beverages such as carbonated or non-carbonated juice beverages, isotonic sports beverages, iced teas, and flavored waters.
Uses
Dimethyl Dicarbonate(DMDC) is a microbial control agent used in wine; ready-to-drink teas; nonjuice-containing beverages; carbonated,dilute beverages containing juice, fruit flavor or both with the juice content not exceeding 50%.
Dimethyl Dicarbonate has been commonly used as a antimicrobial agent for a broad spectrum of microorganisms. The primary target microorganisms of DMDC are yeasts, including Saccharomyces, Zygosaccharomyces, Rhodotorula, Candida, Pichia, Torulopsis, Torula, Endomyces, Kloeckera and Hansenula. DMDC is also bactericidal to a number of species including Acetobacter pasteurianus, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, several Lactobacillus species and Pediococcus cerevisiae DMDC has also been shown to be bactericidal against Escherichia coli O157:H7.
The antimicrobial effect of DMDC results from the deactivation of microbial enzymes, mainly through reaction with protein imidazole and amine groups, leading to the destruction of the microorganisms. The remaining unreacted DMDC breaks down rapidly into methanol and carbon dioxide. The DMDC activity is based on the hydrolysis rate. Hydrolysis occurs when DMDC reacts with water and the rate is dependent on the temperature of the beverage or wine. It takes about four hours at 10°C (50°F) or two hours at 20°C (68°F) for DMDC completely breaking down.
Definition
ChEBI: Velcorin is an organooxygen compound. It is functionally related to a carbonic acid.
Biochem/physiol Actions
Dimethyl dicarbonate (DMDC; Velcorin?) is a colourless liquid with an ester-like pungent odour. DMDC is soluble in water (3.65% solubility), aqueous solutions (e.g. beverages) and alcohol, where it is quickly hydrolysed. This hydrolysis is a quick process: 1 hour at 30°C and within 5 hours at 10°C. DMDC solidifies below 17 °C. It acts as a microbial control agent by inhibiting the enzymes acetate kinase and L-glutamic acid decarboxylase. DMDC undergoes hydrolyses in the presence of water to form primarily methanol and carbon dioxide, which are natural components of fruit and alcoholic drinks.
Purification Methods
Dissolve it in Et2O, shake this with a small volume of 0.1N HCl, dry Et2O with Na2SO4 and distil in in vacuo below 100o to give a clear liquid. It decomposes to CO2 and dimethyl carbonate on heating at 123-149o. It is readily hydrolysed by H2O and is a yeast inhibitor and an IRRITANT. [Brysov et al. J Org Chem USSR 10 2551 1974, Boehm & Mehta Chem Ber 71 1797 1938, Beilstein 3 IV 17.]
