Authenticity of Foods
The geographical origin influences the composition of metabolites e.g. due to different exogenous factors (like soil, temperature, water availability or fertilization). The acquisition of metabolites using NMR spectroscopy (Nuclear Magnetic Resonance) provides a kind of molecular fingerprint that can be analysed using statistical methods, e.g. with regard to the question of geographical origin. Such an analysis of the metabolome enables the detection of a large number of metabolites in a single measurement without the selection of specific analytes (non-targeted analysis). Alternatively, an analysis can be directed against one or more specific metabolites (targeted analysis).
We analyse various plant foods with a particularly high water content (asparagus, truffle) or a particularly high lipid content (hazelnut, walnut). We develop standard methods for sample handling from sample preparation to measurement. An important aspect is the evaluation of the data using statistical methods, in which we cooperate with the research group of Oliver Kohlbacher (University of Tübingen, Applied Bioinformatics).
1H NMR Spectroscopy for Determination of the Geographical Origin of Hazelnuts
René Bachmann, Sven Klockmann, Johanna Haerdter, Markus Fischer, Thomas Hackl
Journal of Agricultural and Food Chemistry 66, 11873-11879 (2018)
Assessment of Mixtures by Spectral Superposition. An Approach in the Field of Metabolomics
René Bachmann, Navid Shakiba, Markus Fischer, Thomas Hackl
Journal of Proteome Research 18, 2458-2466 (2019)
Storage, or infestation with harmful organisms, can significantly deteriorate the quality of a food. The bite into the rancid nut - no pleasure. Infestation with moulds can also lead to contamination by harmful mycotoxins. Here we ask ourselves whether specific metabolic changes can indicate a long storage period or infestation by a harmful organism. Some of the work will be carried out in cooperation with the Bernward Bisping group (University of Hamburg, HAMBURG SCHOOL OF FOOD SCIENCE).
Signal pattern plot: a simple tool for time-dependent metabolomics studies by 1H NMR spectroscopy
René Bachmann, Adelis Jilani, Hasnaa Ibrahim, Dominic Bahmann, Christina Lang, Markus Fischer, Bernward Bisping, Thomas Hackl
Analytical and Bioanalytical Chemistry Online: 16 August 2019 (2019)
Identification of Natural Products/Metabolites from Complex Mixtures
The identification of metabolites from a complex mixture, such as an extract, poses a major challenge. We develop strategies that simplify identification without the time-consuming isolation of individual compounds. We use different methods, such as high-performance liquid chromatography and mass spectrometry in combination with NMR spectroscopy, and make use of the complementarity of the respective methods.
Enzyme kinetics aims at the functional characterization of enzymes, their inhibitors and activators. Depending on the variety of reactions catalyzed by enzymes, a wide range of methods is available for kinetic analyses. NMR spectroscopy is rarely used, although direct quantification is carried out without modification of the substrates and the course of the reaction can be followed in atomic resolution.
NMR for direct determination of Km and Vmax of enzyme reactions based on the Lambert W function-analysis of progress curves
Franziska Exnowitz, Bernd Meyer, Thomas Hackl
Biochimica et Biophysica Acta, Proteins and Proteomics 1824, 443-449 (2012)