Centuries-old recipes give the world-renowned hard cheese from the Emilia-Romagna region its unique character. Parmesan, or Parmigiano in Italian, is traditionally made from raw milk. It needs up to three years to mature before developing the typical taste it is famous for: savory and salty, slightly spicy, but at the same time sour with a bitter-sweet component.
What gives the cheese its overall sensory quality?
Which flavors and aromas are responsible for this? How do they influence our senses? These questions are not only interesting for food lovers, but also for producers who want to test and improve the quality of their products. Scientific investigation methods could help here.
Cheese has long been the subject of research. Studies have shown that various molecules determine the taste. Their composition and concentration are typical for the various types of cheese. For example, γ-L-Glutamyl peptides, which are enzymatically synthesized from amino acids during the cheese maturing process, are primarily responsible for the taste of Gouda. But which substances give Parmesan its unique taste? “Up until now, there were no systematic molecular investigations,” explains Professor Thomas Hofmann, Full Professor at the Chair for Food Chemistry and Molecular Sensory Science TUM.
31 different aromas in Parmesan
Together with Dr. Hedda Hillmann, Hofmann performed a thorough chemical analysis on Parmesan cheese. The researchers broke down the cheese into its components, separated the fats and proteins and concentrated the aromas in an aqueous solution. These were then studied with a high-performance mass spectrometer. 31 different aromas were identified by the TUM team in this way – including minerals, fatty acids, organic acids, biogenic amines and amino acids. Peptides, including γ-L-Glutamyl peptides, were also detected in high concentrations.
Humans and machines in perfect unison
Were all the flavors identified? To test the results, the researchers employed their own trained test persons, who sampled both the Parmesan and the aqueous cheese solution and rated the gustatory impression – for example the categories sweet, salty, sour and bitter. Result: the taste of the aqueous extract was more or less on a par with the taste of the real cheese – which proved that the mass spectroscopic analysis actually reflects the typical distribution of aromas.“The studies give us a molecular, chemosensory fingerprint for Parmesan,” summarizes Professor Hofmann. “This can be useful for objectively measuring and visualizing changes in the taste profile during cheese production. This gives producers the opportunity to improve the taste by changing the process parameters.”
Hedda Hillmann and Thomas Hofmann: Quantitation of Key Tastants and Re-engineering the Taste of Parmesan Cheese, Journal of Agricultural and Food Chemisty, 2016, 64, 1794-1805. 2016, 64, 1794-1805. DOI: 10.1021/acs.jafc.6b00112
Prof. Thomas Hofmann
Chair of Food Chemistry and Molecular Sensory Science
Phone: +49 (89) 289 - 22201 or Phone 2: +49 (8161) 71-2902