Compendium of the most significant studies with reference to properties, intake, effects.

Costa A, Barata A, Malfeito-Ferreira M, Loureiro V. Evaluation of the inhibitory effect of dimethyl dicarbonate (DMDC) against wine microorganisms. Food Microbiol. 2008 Apr;25(2):422-7. doi: 10.1016/j.fm.2007.10.003.

Abstract. Several microbial species associated with wine were challenged against increasing concentrations of dimethyl dicarbonate (DMDC). The concentration inducing complete cell death upon addition to red wine was regarded as the minimum inhibitory concentration (MIC). In dry red wines with 12% (v/v) ethanol and pH 3.50, the inactivation depended on the initial cell concentration. For an initial inoculum of 500 CFU/ml, the MIC of the yeasts species Schizosaccharomyces pombe, Dekkera bruxellensis, Saccharomyces cerevisiae and Pichia guilliermondii was 100mg/l. The most sensitive strains belong to Zygosaccharomyces bailii, Zygoascus hellenicus and Lachancea thermotolerans, with MIC of 25mg/l DMDC. For inoculation rates of about 10(6)CFU/ml, the maximum dose of DMDC legally authorized (200mg/l) was not effective against the most resistant species. The addition of 100mg/l potassium metabisulphite (PMB), equivalent to 1mg/l molecular sulphur dioxide, increased the inactivation effect of 100mg/l DMDC over initial yeast populations of 10(6)CFU/ml but did not fully kill S. pombe and S. cerevisiae. Lactic acid and acetic acid bacteria were not killed by the addition of 300 mg/l of DMDC. Trials performed in wines before bottling showed that in most samples indigenous bacterial populations were not affected by 200mg/l DMDC. Therefore, under winery practice, DMDC at the maximum dose legally permitted may be regarded as an efficient preservative to control low contamination rates of yeasts but ineffective against lactic acid and acetic acid bacteria.

Liu S, Zhang D, Wang Y, Yang F, Zhao J, Du Y, Tian Z, Long C. Dimethyl Dicarbonate as a Food Additive Effectively Inhibits Geotrichum citri-aurantii of Citrus. Foods. 2022 Aug 4;11(15):2328. doi: 10.3390/foods11152328. 

Abstract. Dimethyl dicarbonate (DMDC), a food additive, can be added to a variety of foods as a preservative. This study aimed to evaluate the inhibitory effects of DMDC on Geotrichum citri-aurantii in vitro and in vivo, as well as the potential antifungal mechanism. In vitro experiments showed that 250 mg/L DMDC completely inhibited the growth of G. citri-aurantii and significantly inhibited spore germination by 96.33%. The relative conductivity and propidium iodide (PI) staining results showed that DMDC at 250 mg/L increased membrane permeability and damaged membrane integrity. Malondialdehyde (MDA) content and 2, 7-Dichlorodihydrofluorescein diacetate (DCHF-DA) staining determination indicated that DMDC resulted in intracellular reactive oxygen species (ROS) accumulation and lipid peroxidation. Scanning electron microscopy (SEM) analysis found that the mycelia were distorted and the surface collapsed after DMDC treatment. Morphological changes in mitochondria and the appearance of cavities were observed by transmission electron microscopy (TEM). In vivo, 500 mg/L DMDC and G. citri-aurantii were inoculated into the wounds of citrus. After 7 days of inoculation, DMDC significantly reduced the disease incidence and disease diameter of sour rot. The storage experiment showed that DMDC treatment did not affect the appearance and quality of fruits. In addition, we found that DMDC at 500 mg/L significantly increased the activity of citrus defense-related enzymes, including peroxidase (POD) and phenylalanine ammonia-lyase (PAL). Therefore, DMDC could be used as an effective method to control citrus sour rot.

Mojsov, K., Petreska, M., & Ziberoski, J. (2011). Risks of microbial spoilage of wine: a review.

Abstract. Wines are alcoholic drinks obtained from the fermentation of grapes. The main role of microorganisms in winemaking is to convert grape sugars to alcohol, reduce wine acidity and contribute to aroma and flavor. They can also cause numerous unwelcome wine spoilage problems, which reduce wine quality and value. Winemaking processes includes multiple stages at which microbial spoilage is likely to occur and ends up with altering the quality and hygienic status of the wine. This may render the wine unacceptable, since the spoilage can include bitterness and off-flavours, and cosmetic problems such as turbidity, viscosity, sediment and film formation. The main microorganisms associated with wine spoilage are yeasts, acetic acid bacteria and lactic acid bacteria. A microbial spoilage is the consequence of inadequate working practices. These inadequate practices are derived from two principle attitudes: (1) - non-application of known practices for well identified risks and (2) - insufficient evaluation of risk levels. One of the aims of winemaking is to minimize potential for microbial spoilage and in this review are presented risks of microbial spoilage of wine and their prevention.

Gouma, M., Gayán, E., Raso, J., Condón, S., & Álvarez, I. (2015). Influence of dimethyl dicarbonate on the resistance of Escherichia coli to a combined UV-Heat treatment in apple juice. Frontiers in microbiology, 6, 501.

Abstract. Commercial apple juice inoculated with Escherichia coli was treated with UV-C, heat (55°C) and dimethyl dicarbonate – DMDC (25, 50, and 75 mg/L)-, applied separately and in combination, in order to investigate the possibility of synergistic lethal effects. The inactivation levels resulting from each treatment applied individually for a maximum treatment time of 3.58 min were limited, reaching 1.2, 2.9, and 0.06 log10 reductions for UV, heat, and DMDC (75 mg/L), respectively. However, all the investigated combinations resulted in a synergistic lethal effect, reducing the total treatment time and UV dose, with the synergistic lethal effect being higher when larger concentrations of DMDC were added to the apple juice. The addition of 75 mg/L of DMDC prior to the combined UV-C light treatment at 55°C resulted in 5 log10 reductions after only 1.8 min, reducing the treatment time and UV dose of the combined UV-Heat treatment by 44%.

Taboada‐Rodríguez, A., Belisario‐Sánchez, Y. Y., Cava‐Roda, R., Cano, J. A., López‐Gómez, A., & Marín‐Iniesta, F. (2013). Optimisation of preservatives for dealcoholised red wine using a survival model for spoilage yeasts. International journal of food science & technology, 48(4), 707-714.

Abstract. To optimise the application of preservatives in a new commercial dealcoholised red wine (DRW), a survival model of Rhodotorula mucilaginosa and Saccharomyces cerevisiae was developed. A factorial design included three variables, each at three levels: potassium sorbate, sodium metabisulphite and dimethyl dicarbonate (0, 100 and 200 mg L−1). DRW samples were inoculated with a cocktail of yeasts and counts were performed after 1, 2, 3, 4, 6 and 8 weeks of incubation. Logistic regression analysis was used to create survival models. Potassium sorbate and sodium metabisulphite did not show any fungicide effect alone, while the model predicts that dimethyl dicarbonate at 185 mg L−1 has fungicide activity. The interaction of potassium sorbate and dimethyl dicarbonate was statistically significant, so both could act as synergic preservatives. The logistic model obtained was validated with a 100% of accuracy for the conditions tested. Combining use of the studied preservatives reduced the individual dose for preservation of DRW.

Ruiter, A., & Bergwerff, A. A. (2005). 14 Analysis of Chemical Preservatives in Foods. Methods of analysis of food components and additives, 379.