WASHINGTON — You either love beer, or you run the other way at the sight of it. In an effort to figure out how to make the drink more widely palatable, Belgian scientists have successfully engineered a gene responsible for the strong flavor of beer and other alcoholic beverages.
For centuries, humans brewed beer in large horizontal vats. This changed in the 1970s, as brewers switched to closed vessels that could be easier to fill, empty, and clean. This helped make the process of brewing higher volumes of beer less expensive. The fermentation process converts 50 percent of the sugar to ethanol and the other half to carbon dioxide.
The problem is that the new process leads to the carbon dioxide pressurizing within these closed vessels, which ultimately leads to far lower flavor quality.
This team of researchers applied a technology that they created previously to identify genes in yeast. They were able to use a similar technique in order to identify genes involved in the flavor of beer. To do this, they screened several yeast strains to evaluate which withstood pressurizing and preserved flavor best.
They then turned their focus to a gene that produces a banana-like flavor, “because it is one of the most important flavors present in beer, as well as in other alcoholic drinks,” says Johan Thevelein, Ph.D., an emeritus professor of Molecular Cell Biology at Katholieke Universiteit, in a media release.
They found a mutation within a gene called MDS3, which codes for the same key banana-flavor gene that’s responsible for much of beer’s flavor.
“The mutation is the first insight into understanding the mechanism by which high carbon dioxide pressure may compromise beer flavor production,” says Thevelein.
The team also notes that the MDS3 protein is likely a crucial part of a regulatory pathway that may explain the process of carbon dioxide inhibition, even though mechanisms behind this are currently unclear. The team was able to make this discovery by using CRISPR/Cas9 gene editing technology to engineer a mutation in other types of brewing strains. This ended up showing an ability to resist pressurization and unlock the fullest flavor potential.
“That demonstrated the scientific relevance of our findings, and their commercial potential,” explains Thevelein.
The technology has also proven to be of great benefit in examining the processing of other alcoholic drinks, as well as other commercially valuable scientific components like glycerol production and thermotolerance. The team agrees that technologies like this, along with more affordable sequencing techniques, can analyze food and drinks more carefully.
The findings are published in the journal Applied and Environmental Microbiology.