Media release
From:
Microbiology: How microbes shape Cheddar cheese taste
The combinations of microorganisms responsible for shaping the taste of Cheddar cheese — including fruity, creamy, buttery and nutty flavours — are investigated in a Nature Communications paper.
Cheese fermentation and flavour formation are influenced by complex biochemical reactions driven by microbial activity. Although the compositional dynamics of cheese microbiomes are relatively well mapped, the mechanistic roles of microbial interactions in flavour formation are not fully understood.
To investigate how microbial interactions shape flavour profiles, Chrats Melkonian, Ahmad Zeidan and colleagues prepared year-long batches of Cheddar cheese using variants of a starter culture containing different combinations of Streptococcus thermophilus and Lactococcus strains. The authors identified the important role of S. thermophilus in boosting Lactococcus growth and in shaping the flavour profile. In turn, a strain of Lactococcus cremoris limited the formation of diacetyl and acetoin, which have a buttery flavour but lead to an off flavour when in excess. Additionally, when L. cremoris was removed, four flavour compounds were detected. These included 2,3-pentanedione (which gives the flavour of nuts, cream, and butter), and heptanal and hexanal (which taste fruity and fatty). When L. cremoris was present, another set of flavour compounds was detected in higher amounts such as 2-methyl-3-thiolanone (which adds a meaty flavor) as well as the esters ethyl acetate and ethyl hexanoate (which add a fruity flavour) the authors note.
Overall, the authors suggest their findings highlight the important role of competitive and cooperative microbial interactions in shaping the flavour of Cheddar cheese.