The Germans have taken their love of beer to the next level with a new detailed study of the unique molecules of ales and lagers from around the world.
Scientists in Munich used advanced mass spectrometry techniques on 467 popular beers from Europe, the US and elsewhere.
About 80 percent of the “tens of thousands” of molecules they found are not yet listed in chemical databases, they say.
Their analysis takes only 10 minutes to detect thousands of metabolites in beer, making it a powerful new quality control method.
“Beer is an example of enormous chemical complexity,” said study author Professor Philipp Schmitt-Coplin of the Technical University of Munich.
“With recent advances in analytical chemistry comparable in power to the ongoing revolution in ever-increasing resolution video display technology, we are able to uncover this complexity in unprecedented detail.”
Their state-of-the-art mass spectrometry method can be used for quality control in the food industry, such as identifying any questionable ingredients in beer that violate the Vorläufiges Biergesetz (Provisional Beer Law) 1993.
The Vorläufiges Biergesetz was a revision of Germany’s sacred 500-year-old cleanliness law known as the Reinheitsgebot.
A decree originally introduced by the southern state of Bavaria on April 23, 1516, stated that “no ingredients other than barley, hops and water should be used” in the preparation of beer, although the Germans later realized the importance of the fourth key ingredient in beer, yeast. .
The researchers note that beverages marketed as beer are currently open to a wide variety of brewing types and raw materials, which can lead to adulteration.
“Today, it’s easy to trace tiny variations in chemical composition throughout the food production process to ensure quality or detect hidden adulterations,” said Schmitt-Kopplin.
For the analysis, published in Frontiers in Chemistry, the researchers used 467 beers brewed in the US, Latin America, Europe, Africa, and East Asia, including lagers, craft and monastery beers, top-fermented beers, and Belgian gueuzes. .
They used two powerful methods, Direct Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (DI-FTICR MS) and Quadrupole Time-of-Flight Ultra-Performance Liquid Chromatography (UPLC-ToF-MS).
DI-FTICR-MS can predict the chemical formulas of metabolite ions in beer, while UPLC-ToF-MS uses chromatography to predict their exact molecular structure.
They found about 7,700 ions with unique masses and formulas, including lipids, peptides, nucleotides, phenols, organic acids, phosphates, and carbohydrates, of which about 80 percent are not yet described in chemical databases.
Because each formula can cover up to 25 different molecular structures in some cases, this results in tens of thousands of unique metabolites.
“Here we find a huge chemical diversity of beer with tens of thousands of unique molecules,” said first author Stefan Pechonka, a PhD student at the Technical University of Munich.
“We show that this diversity arises from the diversity of raw materials, processing and fermentation.”
The molecular complexity of beer is enhanced by the so-called “Maillard reaction” between amino acids and sugars.
The Maillard reaction gives bread, steaks, and toasted marshmallows a toasted or sweet malty flavor.
“This complex network of reactions is an exciting avenue for our research, given its importance to food quality and taste, as well as to the development of new biologically active molecules of health interest,” Pechonka said.