FOOD FINGERPRINTING: SEARCHING FOR ADULTERATION OF SPICES AND HERBS BY NON-TARGETED SPECTROSCOPIC ANALYSIS
Janet Riedl, Bettina Horn, Stephanie Panitz, Werner Karl Blaas, Michael Pfister, Susanne Esslinger, Carsten Fauhl-Hassek
Federal Institute for Risk Assessment, Germany
Securing food chains from primary production to consumer ready food against any kind of contaminations and/or adulterations is a prerequisite for food safety. Usually analytical methods are available or can be developed that allow the quantification of certain contaminants or adulterants. However, fraudsters may add substances or mixtures of an unforeseen nature to a commodity, which might not be covered by the available targeted methods. The detection and subsequent chemometric analysis of the whole spectra of a sample in a non-targeted analytical approach may allow determining deviations from typical products characteristics, including the addition of unknown adulterants.
As spices and herbs are typically high-price commodities, fraudulent practices promise high economic profit. Therefore, it is not surprising that spices and herbs are often reported cases of food fraud. One main objective of the EU-project SPICED is the development of such non-targeted analytical approaches for the detection of unforeseen chemical agents to reduce chemical adulterations and to ensure the authenticity of spices and herbs. For this purpose, a representative set of authentic as well as adulterated (spiked) samples of oregano, nutmeg or paprika were investigated by nuclear magnetic resonance (1H -NMR) spectroscopy and Fourier transform infrared (FT-IR) spectroscopy. The authentic data set serves as basis for the determination of critical limits of a typical product range to then identify potentially adulterated samples. The samples spiked with product foreign or own plant material as well as with concealing agents were used to challenge suitable statistical approaches. The basic ideas and selected results of this project will be presented.
Janet Riedl graduated in Chemistry and Toxicology at the University of Leipzig (Germany) and received her Ph.D. for the application of metabolomics in ecotoxicology from the Technical University Bergakademie Freiberg in 2014 (Germany). From 2008 to 2012 she investigated the metabolome of higher aquatic plants with GC-MS at the Helmholtz Centre of Environmental Research in Leipzig. Currently she is a post-doctoral researcher at the Federal Institute for Risk Assessment in Berlin (Germany) involved in the fingerprinting analysis of wine, spices and maize with NMR and FT-IR. Her focus is on plant systems and pattern-based data analysis in ecotoxicology and food authenticity and the validation of metabolic fingerprinting approaches.