Organic food is booming – but was the much more expensive tomato really grown organically? This can be found out by means of an analytic technique that scientists from the university of Würzburg are working on.
The demand for organic food is rising. It has almost tripled worldwide between 2002 and 2011, despite the fact that organic food is much more expensive than products grown the usual way. This has tempted some manufacturers and vendors to pass conventional goods off as organic – to the detriment of the consumer.
Organic tomatoes rooting in earth, here in a greenhouse of the Bavarian State Institute for Viticulture and Horticulture (LWG) in Veitshöchheim.
Current analytics is not good enough
Laboratory analyses are currently not completely capable of determining whether vegetables and fruit were really produced organically. The most reliable method at the moment is to examine the different forms (isotopes) of nitrogen in tomatoes, leek, or broccoli.
“However, it is not always possible to achieve a clear result with this method,” says food chemist Monika Hohmann, doctoral student at the University of Würzburg and at the Bavarian Health and Food Safety Authority (LGL). One of the reasons is that certain fertilisation methods in organic farming prevent a clear distinction in the isotope analysis between the nitrogen composition resulting from organic and conventional fertilisers.
Magnetic resonance spectra as an alternative
This is why Hohmann developed a different method with promising first results: Using the so-called magnetic resonance spectroscopy (NMR), she created a kind of fingerprint of the contents of tomatoes, and the interpretation of the results showed significant differences between the organically and conventionally grown tomato varieties “Mecano” and “Tastery”. This is reported by Hohmann and her dissertation supervisors Norbert Christoph, Helmut Wachter, and Ulrike Holzgrabe in the “Journal of Agricultural and Food Chemistry”.
The scientists are collaborating on this project with the Bavarian State Institute for Viticulture and Horticulture (LWG) in Veitshöchheim, where tomatoes in the greenhouse are grown organically and conventionally under strictly defined conditions. Samples are taken regularly, pureed, and centrifugalised. Finally, Hohmann measures a so-called 1H-NMR spectrum of them.
More tomato varieties to be included
“We are building up a data base from the spectra and this enabled us to detect the differences between the organically grown tomatoes and the conventional ones in the test setup,” Hohmann says. Up until now, only two tomato varieties were examined by the doctoral student. As a next step, she also wants to analyse other varieties, because it became obvious that differences between the varieties must be taken into account. Is this method also suitable for other fruit and vegetables? This is another question that will have to be clarified.
The scientists see their current results as a good starting point for developing a reliable method for a clear identification of organically produced tomatoes and other foods. Fraudsters passing off conventional fruit and vegetables as “organic” will not really like this.
Supervision and funding of the research
Monika Hohmann conducts her doctoral thesis at the Bavarian Health and Food Safety Authority (LGL) in Würzburg. Her supervisors are Norbert Christoph and Helmut Wachter. Her mentor at the University of Würzburg is Professor Ulrike Holzgrabe, who runs the Department of Pharmaceutical Chemistry. One of Holzgrabe’s areas of expertise is the detection of counterfeit medications using NMR.
The project at the LGL is funded by the Bavarian Ministry for Environment and Consumer Protection.
1H NMR Profiling as an Approach To Differentiate Conventionally and Organically Grown Tomatoes, Monika Hohmann, Norbert Christoph, Helmut Wachter, and Ulrike Holzgrabe, J. Agric. Food Chem., 2014, 62 (33), pp 8530–8540, DOI: 10.1021/jf502113r
Bavarian Health and Food Safety Authority (LGL), Department R 4.1, Luitpoldstraße 1, 97082 Würzburg, T +49 (0) 9131 6808-2424, email@example.com
Robert Emmerich | idw - Informationsdienst Wissenschaft
Chains of nanogold – forged with atomic precision
23.09.2016 | Suomen Akatemia (Academy of Finland)
Self-assembled nanostructures hit their target
23.09.2016 | King Abdullah University of Science and Technology
The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.
“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...
With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.
Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...
For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.
Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...
At AKL’16, the International Laser Technology Congress held in May this year, interest in the topic of process control was greater than expected. Appropriately, the event was also used to launch the Industry Working Group for Process Control in Laser Material Processing. The group provides a forum for representatives from industry and research to initiate pre-competitive projects and discuss issues such as standards, potential cost savings and feasibility.
In the age of industry 4.0, laser technology is firmly established within manufacturing. A wide variety of laser techniques – from USP ablation and additive...
Every three years, the plastics industry gathers at K, the international trade fair for plastics and rubber in Düsseldorf. The Fraunhofer Institute for Laser Technology ILT will also be attending again and presenting many innovative technologies, such as for joining plastics and metals using ultrashort pulse lasers. From October 19 to 26, you can find the Fraunhofer ILT at the joint Fraunhofer booth SC01 in Hall 7.
K is the world’s largest trade fair for the plastics and rubber industry. As in previous years, the organizers are expecting 3,000 exhibitors and more than...
23.09.2016 | Event News
20.09.2016 | Event News
16.09.2016 | Event News
23.09.2016 | Life Sciences
23.09.2016 | Health and Medicine
23.09.2016 | Life Sciences