Future Food Forensics
It’s time to introduce gold standard analytical science in the fight against food fraudsters.
Dietmar Knopp |
Scared by spectacular news stories in the media, my friends and I are paying much more attention to the quality of our food. Our most serious concern is the risk of food poisoning by harmful microorganisms such as E. coli O157:H7 or Salmonella, or by natural toxins, such as mycotoxins. The second important health issue we’ve recognized is the misuse of animal drugs, especially antibiotics. Who wants unauthorized medical treatment leading to the cultivation of multidrug-resistant bacteria? And let’s not forget the third risk of allergic reactions – or even death – caused by poor or incorrect food labeling...
Beyond worrying about our health, other food safety and authenticity issues can affect food quality and contravene ethical (vegetarians) or religious (halal) choices. Disregarding accidental mislabeling, such issues are becoming increasingly common as fraudsters try to profit from selling food to unsuspecting victims. Globalization and rapid distribution systems have made food fraud a problem of international scale.
Fraud is very simple: take money for a high-quality product but provide a lower-grade item. Fraudsters swap the main ingredient with a similar product that is cheaper or they may extend or adulterate the food with cheaper material (you may remember the horsemeat scandal). They may not declare all of the ingredients and may lie about the manufacturing process/location or geographical origin.
As an analytical scientist, should I have blind trust in existing and new methodologies? Are they robust and reliable enough to ensure honest and accurate food labeling? I have my doubts – after all, each analytical method has its pros and cons. Traditional analytical methods for food authentication determine components using wet chemistry and chromatography or measure stable isotope ratios and trace elements. Wouldn’t it be more reliable to measure several components (the more the better) in one single analysis, making it non-targeted?
There are several emerging non-targeted approaches that aim to create a profile (the ‘metabolome’) of as many metabolites as possible in the sample. Typically, they employ ‘fingerprinting’ detection methods such as non-invasive vibrational spectroscopic techniques (NIR, MIR, FTIR, and Raman), nuclear magnetic resonance (NMR) spectroscopy and an increasing range of mass spectrometry (MS)-based techniques. However, larger databases and improved multivariate data analysis tools need establishing to ensure success. That said, I am somewhat optimistic about the prospects of these new developments.
Targeted approaches focus on a defined group of key biomarkers, and can certainly indicate the presence of a specific type of food and/or adulterant. The current gold standard here is performed using robust and highly discriminating MS-analysis (proteome analysis) using ESI and MALDI or the rapidly evolving genetic methods that apply a set of different specific DNA molecular markers followed by highly specific amplification through PCR techniques.
I’ve always been inspired by the outstanding properties of biomolecules, especially antibodies. Different formats of immunoassay, such as ELISA, immune ‘dot blot’, Western blot coupled with lateral flow devices constitute fast and cost-effective tools for routine screening of allergens, GMOs, seafood and fish, meat, milk and dairy products, feedstuffs and fruit juice. To date, the main disadvantages are the limited availability of commercial antibodies and kits, problems in the analysis of highly processed or complex food matrices, and unsatisfying parallel identification and reliable quantification of multiple biomarkers. Automated antibody (or lectin) chip arrays or bead-based immunoassays are promising assay formats and may provide the necessary flexibility, sample throughput and robustness for routine screening in the future.
Although the art of food authentication focuses primarily on consumer safety, the economic impact on genuine producers and processors is becoming increasingly important. Though food fraud and other illegal activities in the industry are hampered by different national and international regulatory requirements, it is analytical chemistry that will provide the winning solutions. And I’m sure bioanalytical methods will increasingly help in our response to the challenges of food forensics.
Fascinated by the formidable efficiency of the immune system while studying biochemistry at the University of Leipzig, Germany, Dietmar Knopp became one of the very first scientists who tackled the preparation and use of high affine antibodies for analytical determination of small environmental and food related chemicals. His radioimmunoassay for the herbicide 2,4-D, reported in 1985, was the starting point of a scientific career that began in 1991 at the Technische Universität München, Germany, where his research focuses on the exploration of different kinds of biomolecules – mainly antibodies – and assay formats for rapid, highly sensitive and specific bioanalyses of trace amounts of chemicals in complex matrices.
