Scientists in Germany have developed a new method to analyze flavor-relevant peptides formed during cheese ripening, which they say are crucial for the “full-bodied flavor” of aged cheeses, known as kokumi. The team also analyzed 120 cheese samples and created a database that can be used to predict flavor development during cheese ripening or to formulate plant-based cheese products.

Cheese is an integral part of the Western diet. Some 54% of consumers prefer aged cheese to products with a shorter aging period, according to the Leibniz-Institute for Food Systems Biology at the Technical University of Munich, Germany, which led the research. only 16% favor shorter-aged varieties.

This could be because the “long-lasting taste experience” is particularly pronounced in aged cheeses, mainly due to the increasing concentration of gamma-glutamyl dipeptides.

Predicting and monitoring flavor development

The study’s findings, published in Food Chemistry show that the concentrations of these glutamyl dipeptides rise with increasing ripeness. 

“Interestingly, the addition of blue and white mold cultures led to significantly higher gamma-glutamyl dipeptide concentrations, even at shorter ripening times,” says Andreas Dunkel, who led the research and also heads the Integrative Food Systems Analysis research group at the Leibniz Institute.

“The concentration profiles we have determined for different stages of ripening and different types of cheese can be used in the future as a database for prediction models.”

The database can be used to “objectively monitor flavor development during cheese ripening, to shorten ripening times or to develop new plant-based cheese products with high consumer acceptance,” he adds.

Accelerating analysis

The researchers flag that the high polarity of glutamyl dipeptides and their high structural similarity with different flavor contributions pose a challenge for food analysts.

To overcome this hurdle, the team based their new method on ultra-high-performance liquid chromatography-mass spectrometry techniques, which can “determine the concentrations of all 56 gamma-glutamyl dipeptide variants in just 22 minutes.” 

Additionally, by optimizing sample preparation, they can analyze 60 cheese samples per day.

“This is a significant improvement compared to other methods. Our tests have shown that our method is faster, more efficient and yet reliable — it delivers reproducible results and detects even the smallest concentrations,” says first author Sonja Maria Fröhlich, a doctoral student at the Leibniz Institute.

To further investigate the influence of ripening time on gamma-glutamyl dipeptide concentrations, the researchers applied the method to 122 cheese samples from Europe and the US after the test phase. The cheese’s ripening times ranged from two weeks to 15 years.

German cheese advances

Gouda, Edam and quark are among Germany’s most produced types of cheese, Statista figures indicate. In 2022, Germans consumed around two million metric tons of cheese, corresponding to a per capita consumption of around 24 kg of cheese per year.

Globally, the cheese market has been steadily increasing throughout the past five years, growing by 3% in sales and 2% in volume, suggests Innova Market Insights data. While the US dominates sales, Germany, France, Russia and Italy trail behind, says the market researcher’s report on global dairy and non-dairy cheese innovation and preferences.

Last month, German packaging manufacturer MBM Innovations combined its VSM vacuum packaging technology with dsm-firmenich’s maturation membrane to optimize the maturation process of aged cheese and reduce costs for producers and consumers.