Methanol contamination in traditionally fermented alcoholic beverages: the microbial dimension.

Elijah Ige Ohimain

doi:10.1186/s40064-016-3303-1

Abstract

Incidence of methanol contamination of traditionally fermented beverages is increasing globally resulting in the death of several persons. The source of methanol contamination has not been clearly established in most countries. While there were speculations that unscrupulous vendors might have deliberately spiked the beverages with methanol, it is more likely that the methanol might have been produced by contaminating microbes during traditional ethanol fermentation, which is often inoculated spontaneously by mixed microbes, with a potential to produce mixed alcohols. Methanol production in traditionally fermented beverages can be linked to the activities of pectinase producing yeast, fungi and bacteria. This study assessed some traditional fermented beverages and found that some beverages are prone to methanol contamination including cachaca, cholai, agave, arak, plum and grape wines. Possible microbial role in the production of methanol and other volatile congeners in these fermented beverages were discussed. The study concluded by suggesting that contaminated alcoholic beverages be converted for fuel use rather than out rightly banning the age—long traditional alcohol fermentation.

Highlights

Beverage ethanol production via fermentation is an age long tradition in many parts of the world
The aim of this review is to present alternative viewpoint showing the possible role of microbes in the production of methanol in traditionally fermented beverages
We reviewed literatures on traditionally fermented alcoholic beverages, assessed the methanol content of the beverages, the pectin content of their feedstocks and the microbial species involved in the fermentation in an attempt to establish a possible role of microbes in the production of methanol in traditionally fermented alcoholic beverages

Summary

Introduction

Beverage ethanol production via fermentation is an age long tradition in many parts of the world. In the tropical world and elsewhere, indigenous people are involved in the entire value chain of traditional alcohol fermentation. Jespersen (2003) reported that most beverages and foods in Africa are produced at household level or on small industrial scale often of varying qualities. Aiyeloga et al (2014) reported the potentials of raffia palm wine in sustaining livelihood in rural and urban populations in Nigeria. In Africa, Asia and South America, there has been an increasing incidence of methanol contamination in traditionally fermented alcoholic drinks (WHO 2014). Several cases of methanol poisoning have been reported in India and elsewhere. For instance in 2008, over 180 persons were killed in Bangalore and in

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Conclusion