Scientists have precisely identified the bacteria that make cheese fruity, musty or oniony
Cheesemaking has been around for thousands of years, and there are now more than 1,000 varieties of cheese around the world. But why some cheeses, like Parmesan, taste fruity while others, like Brie and Camembert, taste musty remains a mystery. Now scientists have identified specific types bacteria that produce these flavor compounds .
The conclusions described on November 10 in Microbiology Spectrum could help cheese makers fine-tune cheese flavor profiles to better match consumer preferences, say food microbiologist Morio Ishikawa and colleagues.
The taste of cheese depends not only on the type of milk and leavens used to prepare the sour-milk delight. Constellation of organisms which move during the ripening process of the cheese, also contribute to the taste.
Ishikawa of the Tokyo University of Agriculture compares these non-starter bacteria to an orchestra. “We can perceive the sounds of a cheese orchestra as harmony, but we don’t know which instruments each one is responsible for.”
Previous research by Ishikawa and his colleagues used genetic analysis, gas chromatography and mass spectrometry to link specific aroma molecules to specific types of bacteria on moldy surface cheeses made from pasteurized and raw cow’s milk in Japan and France.
In the new study, to show that each suspected bacterium was responsible for producing the flavor compound it was associated with, the team released each type of microbe on its own sample of unripened cheese. The researchers then observed how the flavor compounds in the cheese changed over 21 days.
It is noteworthy that Pseudoalteromonas — a genus of marine bacteria found in various cheeses—produces the largest number of flavor compounds. And the microbes produced esters, ketones, and sulfur compounds, which are known to give cheese its fruity, moldy, and oniony flavors.
In addition to helping to improve popular cheeses, Ishikawa says, the discovery could help cheesemakers conduct new orchestras that will play new harmonies.
