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Cocoa beans, when fermented properly, have a pleasant smell with sweet and floral notes. But they can have an off-putting scent when fermentation goes badly, or when storage conditions aren’t quite right and microorganisms thrive in them. If these grains go into the manufacturing process, the final chocolate can have an unpleasant odor. The researchers had previously used molecular techniques to identify compounds that contribute to unwanted smoky flavors.

Using gas chromatography in combination with olfactometry and mass spectrometry, researchers at the Technical University of Munich, Germany, identified 57 molecules that made up the olfactory profiles of normal-smelling cocoa beans. and moldy / moldy. Of these compounds, four had higher concentrations in low odor samples.

Researchers have determined that geosmin – associated with musty and beetroot odors – and 3-methyl-1H-indole – associated with fecal and mothball odors – are the main contributors to musty and musty odors in cocoa beans. . According to a statement from the American Chemical Society, they found that geosmin was mainly found in the bean shells, which are removed during processing, while the latter was mainly found in the bean tip which is turned into chocolate. Researchers say measuring the amount of these compounds in cocoa beans could be an objective way to spot off-putting flavors and scents.