Ever wonder how different types of cheese can taste so different when the base ingredients are basically the same? What contributes to the different flavors of cheese? Those who have read up on cheese fermentation would find that microbes and differences in fermentation conditions lead to the different delicious cheeses. However, if cheesemakers were asked to pinpoint the microbes responsible for each specific aspect of cheese flavor, they would struggle to answer. One study, led by Aaron Walsh and Guerrino Macori from the Teagasc Food Research Centre in Ireland, did an in-depth analysis of all the microbes present in 55 artisanal Irish and 107 publicly available cheese datasets in order to provide a better understanding of how the taste and quality of cheese are affected by microbes. 

Compounds produced by microbes in cheese determine the final flavor and color of cheese. The genes that a microbe has determines if the microbe can produce a specific compound or not. So, in order to pinpoint the microbe responsible for a particular flavor, this study sequenced and assembled the DNA to find what genes each microbe has. The DNA was then analyzed in-depth to determine which specific microbe could be responsible for a certain flavor or color of cheese. New microbes were found in the cheese datasets and these microbes produced compounds (acetate, succinate, lactate, or ammonium), which could increase the fruity, umami, sour, or licorice-like flavors. In addition, the study determined that specific microbes are potentially important for producing a specific compound by correlating the increased presence of a specific microbe to increased compound amounts, and vice versa. This study produced a vast amount of information on what each type of microbe could be doing.

Armed with the knowledge from this study, researchers and cheesemakers could potentially start making new flavor profiles that were originally unique to certain regions with less trial and error. The information can ultimately be used to optimize multiple aspects of cheese production, such as improving cheese flavor (addressed in this blog), appearance, quality, and safety. 

Managing Correspondent: Jenny Zheng

Press article: https://phys.org/news/2020-08-cheese-insights-age-old-food.html Phys.org

Original article: https://www.nature.com/articles/s43016-020-0129-3 Nature Food

Image Credit: https://pixabay.com/photos/käseplatte-cheese-buffet-1108564/