Research group Prof. Dr. Stephan Schwarzinger
Authenticity and quality of foodstuffs and materials - CSI-Food Bayreuth
High quality foods command higher prices. Especially if they come from specific regions or make special health claims. This applies not only to consumer prices, but also along the entire value chain, i.e. also to producers, processors and refiners, bottlers, and retailers. However, the information given on origin and quality is often incorrect - or even deliberately misstated in order to achieve higher revenues. This is called economically motivated food fraud. In such cases, not only consumers suffer detriment, but also the traders, processors, bottlers, etc. involved.
Our laboratory is therefore working on the development of analytical methods to prevent food fraud and to ensure safety and fairness throughout the value chain.
Methods
Because the quality and authenticity of food does not usually depend on a single test parameter, and because counterfeiters often deliberately mask their manipulations, we work with methods that can quickly record a large number of test parameters: In other words, we digitize foods and create virtual fingerprints of their ingredients. This enables us to quickly obtain a first overall impression of the sample being analysed within just a few minutes.
As a rule, there is not a single method that can provide safety in all respects - nature is too diverse and food too complex. Therefore, our group uses various multi-parameter methods, in particular NMR spectroscopy, mass spectrometry and optical, infrared (IR)-based methods. We often combine these with other classical reference methods (see equipment list) to ensure the validity of the newly developed screening methods.
Chemometry
... is a comparatively new discipline in chemistry. Essentially, it is about establishing connections between complex chemical analysis data and certain facts, such as a certain region of origin or method of cultivation. In order to be able to combine data from our projects (yes, we make big data even bigger), our group is developing a unique software tool. Among other things, we are able to identify combinations of methods in order to solve problems that cannot be dealt with using one method alone. These often involve questions of geographical origin or cultivation methods, i.e. whether it’s organic or not.

Origin of olive oil: Chemometric evaluation of NMR oil profiling data (in cooperation with ALNuMed GmbH and DOP e.V.). Ingredient fingerprints also provide information about the origin of an olive oil sample.
Broad applicability
We are currently conducting intensive research on honey, cereals (AgrOr project), edible oils, cocoa, beverages (including energy drinks), fish & meat, and other predominantly vegetable foods. Besides this, we routinely carry out feasibility studies for new food products. However, our spectroscopic methods are not limited to foodstuffs. Especially our IR-based optical methods can be used very efficiently for material testing. Even gemstones can be tested for authenticity...
Videos
- Aktuell: Fake Food – Die Tricks der Lebensmittelfälscher (ZDF, 2019)
- Campus Talks: Lebensmittelfälschern auf der Spur (BR-Alpa, 2018)
- Markt-Check (SWR): Mit Sirup gestreckt? Wie echt ist Honig aus dem Supermarkt? (SWR, 2018)
- Campus-DLD 2018: Food-Fingerprinting – Digitalisierung von Lebensmitteln
- Woher kommt eigentlich unser Honig? (Galileo – ProSieben, 2017)
- Ernährung: Unser Essen in der Zukunft – Teil 3 (BR – Alpha, 2015)
Publications:
- APIMONDA Work group "Adulteration" (unter Beteiligung von S. Schwarzinger): APIMONDIA Statement on Honey Fraud. APIMONDIA web site, 2019.
- S. Schwarzinger*, F. Brauer, P. Rösch, B. Schütz, B. Kämpf, G. Beckh, C. Lüllmann, A. Dübecke (2016): Authentische Lebensmittel – Warum ein Analyseparameter nicht genügt. Q & More online.
- S. Hellbach, P. Rösch, S. Schwarzinger* (2017): Restoring consumer confidence by rapid authenticity & identity testing for fruit juices and juice ingredients. Fruit Juice Focus 2/’17, 14-15.
- S. Schwarzinger*, F. Brauer, P. Rösch, B. Kämpf (2016): Honey, what else? Rapid testing of variety geographic origin, and absence of adulteration by NMR-profiling. New Food 6, 27 – 31.
- S. Schwarzinger*, P. Rösch, B. Kämpf (2015): Mit Hightech gegen Honigverfälschung. Deutsches Bienenjournal 2. 2015.
- W. Bachert, L. Köberle, F. Brauer, P. Rösch, S. Schwarzinger* (2014): Mehr als Honig? Q & More 2.14, 36-43.
- S. Schwarzinger*, J. Mitsotakis, L. Köberle, F. Brauer, P. Rösch, (2014): Authentische Lebensmittel haben Mehrwert – Hochdurchsatzfähige Qualitäts- und Authentizitätsprüfung mittels NMR. FOOD-Lab, 2/2014.
- L. Köberle, F. Brauer, P. Rösch, S. Schwarzinger* mit K. Tröger, K.-H. Schwind, F. Schwägele (2013): Was essen wir? Qualitätsanalytik von Lebensmitteln durch NMR. Q & More, 02.13, 42-47.