Food fraud has become a lucrative multimillion-dollar industry, that has seen remarkable growth in recent years. Given the complex nature of the food supply chain, traceability using documents and papers has become extremely difficult, mainly because they are easy to forge. Addressing this challenge requires the application of objective methods of analysis. In this context, non-targeted metabolomics strategies using mass spectrometry techniques are proving to be a promising solution.
The focus of the lecture is initially on the adulteration of various species of truffles. Truffles are one of the most expensive foods in the world. The various species differ in their aroma and in their culinary value. These differences in quality are also reflected in the price, which is why it is worthwhile to re-declare inferior truffle species as more expensive species. Using mass spectrometry, several hundred signals were extracted that were present in the analyzed truffle species in significantly different concentrations. Just a few marker substances are sufficient to reliably distinguish between the different species of black and white truffles [1].
The second part of the lecture deals with the adulteration of oregano (Origanum vulgare and O. onites) with marjoram (O. majorana). Oregano is one of the most frequently counterfeit spices in the world. In addition to olive leaves, oregano is particularly mixed with marjoram leaves in order to achieve a higher financial profit. Although many analytical methods have already been developed to verify the authenticity of oregano, only one marker compound (arbutin) is currently known that can be used to detect the addition of marjoram in oregano. Additional validation of the analysis with other marker compounds is desirable, as it cannot be ruled out that the known marker is also contained in other spices. The analysis of mixtures and the detection of marker compounds, with which marjoram can still be detected in oregano in relatively small admixtures of approx. 5% proved to be challenging. Although mass spectrometric analysis in positive and negative ionization modes was able to detect around 3,000 features, only one marker compound proved to be suitable for detecting marjoram in oregano, even in small proportions. Based on MS/MS spectra and collision cross-section (CCS) values recorded with an ion mobility cell, the compound was identified as blumeatin [2].
Literature:
[1] Creydt M, Fischer M, Molecular Omics 2022, 18, 161 [2] Creydt M, Flügge F, Dammann R, Schütze B, Günther U, Fischer, M, Metabolite 2023, 20, 13.
