Let it Brie: Using the Non-Destructive SepQuant DropletProbe Sampling System to Analyze the Free Amino Acid Content of Various Cheeses

• Published in: Journal of biomolecular techniques Vol. 30; no. Suppl; p. S24
• Main Authors: Tilley, Sloane, Kertez, Vilmos
• Format: Journal Article
• Language: English
• Published: United States Association of Biomolecular Resource Facilities 01.12.2019
• Subjects: Poster Abstracts
• ISSN: 1524-0215; 1943-4731

Casein proteins are an important energy source for the microbial communities that drive the complex process of surface-ripening of various types of cheese. The process of proteolysis involves cleavage of these caseins into smaller peptides, then free amino acids, and culminates in amino acid catabolism, which is one of the primary biochemical reactions that produces flavor in cheese. Here, we aimed use the SepQuant dropletProbe, an innovative liquid extraction surface analysis sampling system, coupled to high performance liquid chromatography-mass spectrometry (HPLC-MS) to profile the free amino acid content of 12 different cheeses. Using this approach, we were able to detect 17 separate amino acids across 37 samples, as well as to compare and contrast the free amino acid profiles within and between samples. The ability of the SepQuant dropletProbe to automate extraction and to accommodate samples of varying heights eliminated extensive sample preparation steps that are usually required for this type of biochemical analysis. Results indicated that the relative quantity of free amino acids varies in association with cheese hardness and between the rind and body sections of cheeses. Unique to this study, we were also able to observe that the relative quantity of amino acids varies within the sample (e.g. between the inner and outer parts of the rind). In this study, we demonstrated that the SepQuant dropletProbe sampling system is a sensitive, efficient, and non-destructive method to characterize the free amino acid content of many different types of cheese. Future research could aim to apply this same concept to a variety of different known flavor compounds in cheese and other foodstuffs and to monitor the production of flavor compounds from the same sample in situ over the course of time.