Peptides formed during cheese ripening play a vital role in the development of the full-bodied flavor found in aged cheeses, also known as kokumi. A research team led by the Leibniz-Institute for Food Systems Biology at the Technical University of Munich has created a new method to analyze these flavor-relevant peptides accurately, quickly, and efficiently. Through the analysis of over 120 cheese samples, the team has established a comprehensive database that can be utilized to predict flavor development during the cheese ripening process in the future.
The term kokumi, originating from Japanese, describes a rich and long-lasting taste experience that is especially prominent in aged cheeses. This flavor profile is mainly attributed to the increasing concentration of gamma-glutamyl dipeptides, which are small molecules consisting of a bond between glutamic acid and another amino acid. Researchers categorize these dipeptides into gamma-, alpha-, and X-glutamyl based on the specific linkage of the two amino acids, with only gamma-glutamyl dipeptides contributing to the kokumi effect. The high polarity and structural similarity of these peptides pose a challenge for food analysis.
The research team, led by principal investigator Andreas Dunkel, has successfully developed an efficient analysis method using ultra-high performance liquid chromatography-mass spectrometry. This innovative approach allows for the precise and selective determination of all 56 gamma-glutamyl dipeptide variants in a mere 22 minutes. With optimized sample preparation techniques, the researchers can analyze up to 60 cheese samples per day, offering faster and more efficient results with high reliability and reproducibility.
In their study, the researchers applied their analysis method to 122 cheese samples from Europe and the USA to investigate the impact of ripening time on gamma-glutamyl dipeptide concentrations. The results confirmed that as cheeses matured, the concentrations of these flavor-active peptides increased. Interestingly, the addition of blue and white mold cultures during the cheese-making process led to significantly higher concentrations of gamma-glutamyl dipeptides, even with shorter ripening times.
Andreas Dunkel, head of the Integrative Food Systems Analysis research group at the Leibniz Institute, emphasizes the potential applications of their findings. The concentration profiles established for various ripening stages and cheese types can serve as a valuable database for developing predictive models to monitor flavor development during cheese ripening objectively. These models could potentially aid in shortening ripening times or creating new plant-based cheese products tailored to consumer preferences.
Veronika Somoza, the director of the Leibniz Institute, highlights the interdisciplinary approach taken by the research team, combining analytical research with bioinformatic methods to create predictive models that support sustainable food production. This innovative research initiative spearheaded by Andreas Dunkel aims to revolutionize the food industry by harnessing cutting-edge technology to enhance the flavor profiles of cheeses and develop novel plant-based alternatives that meet consumer demands.