Complex food supply chains in the current global market require a farm-to-fork approach to ensure supply chain integrity for delivering safe and authentic food. Although there is no precise evaluation on the impact of “economically motivated adulteration” (EMA) food fraud, it has been estimated that intentionally adulterated food could impact 10-15% of all food products and an estimated $10-15 billion globally.
Detection and quantification of adulteration and fraud in complex food will always be a challenge due to lack of universally applied standards. The UN’s Codex Alimentarius Commission has established many product standards that include some detailed compositional criteria. However, with very few exceptions, there are still significant challenges to correlating Codex or national food product compositional standards and private e product characteristics and specifications against objective and repeatable sensory or analytical tests. Foods and food ingredients commonly associated with food fraud include olive oil, fish, honey, milk and dairy products, meat products, grain-based foods, fruit juices, wine and alcoholic beverages, organic foods, spices, coffee, tea, and some highly processed foods
For the food processing industry and consumers, the impact of food fraud is not only economic: It also has the potential to have a tremendous negative impact on public health. One well-known and specific food fraud example is the addition of melamine to falsify protein levels in pet food, infant formula and milk-based products by artificially inflating protein values. Adulterated pet food ingredients from China and melamine-contaminated infant formula have sickened an estimated 300,000 Chinese children and reportedly killed six infants. Another example of “pure” food fraud was reported in the European Union, where a significant amount of horse meat, confirmed by DNA testing was found in beef burgers.
Fortunately, scientific achievement and technologies can enhance consumer protection and combat the food fraud and adulteration problem. The analytical capability provided by advanced DNA measurements of many foods such as meat, seafood and spices can create a reference “footprint” that allows researchers, analytical testing laboratories, state and federal regulators, the food processing industry and consumers to have increased confidence that the foods they regulate or buy are exactly as represented.
Detection advances
Verification of a food’s identity and needed advancements in laboratory methodology to ensure a reliable and affordable approach has been a long and highly pursued goal. Of the current DNA-based methods, polymerase chain reaction (PCR), including quantitative PCR (qPCR), provides sensitive, reliable and repeatable detection methods in food matrices. However, the challenge is that this method cannot identify untargeted DNA in the matrix component. In other words, we cannot detect any “unknown” ingredients if they are not identified using this method.
Enter next-generation sequencing (NGS) technology, which recently has been applied to detect plant and animal species in a few food adulteration cases. NGS employs a different approach compared with the targeted genome identification systems for detecting a specific species. This method uses a procedure to produce a more variable and more in-depth genome sequencing dataset to find food-related genes for verification of the actual food’s content, ingredients, sourcing and label.
Some of the examples are, but not limited to, the addition of bovine material to chicken fillets and species determination of meats, fish, spices and seafood whereby fraudulent products contain a lower valued species.[1] These methods are largely qualitative, specific and sensitive in terms of lower limits of applicability.
In addition to food fraud, NGS could be an extremely effective way for helping food suppliers and processors in many other ways, such as determination of microorganisms in the production environment. This ability would generate a valuable and unique opportunity for the food manufacturing industry to have more confidence in the background and resident microbiology of the processing environment, which will make the job of regulators easier, fortify industry food safety programs and protect consumer health.
One of the main challenges of the NGS is extracting the proper amount of and “right” type of DNA in a food matrix without damaging the majority of the food DNA through the processing steps. Figure 1 demonstrates the major three steps for food fraud detection using NGS technology. Variations on each step depend on the sample type, size and investigation plan. For example, the DNA extraction step could be varied based on the food type and food matrix complexity. The sequencing steps using the four indicated methods — Ion Torrent, Illumina, Nanopore and Single Molecule Real Time — also are varied according to the required sensitivity and specificity of the DNA sequencing method.
Leveling up your testing
NGS is revolutionizing food fraud verification by using genetic sequencing of the actual food’s contents and ingredients to confirm shipping and labeling documentation. Using these advanced laboratory methods will provide all with new tools to effectively detect food fraud. These new analytical tools will require new levels of expertise and an understanding of the benefits and limitations of this advanced technology as they are further developed and utilized in the food processing industry.
— By Mehrdad Tajkarimi, Ph.D., an EAS Consulting Group independent consultant who is an expert in national and international food safety regulations, warehouse and wholesale manufacturing, dairy, grain, poultry and retail industries, HACCP, food defense, ISO 22000 and BRC.
Sources
1. Hong, E., et al. Modern analytical methods for the detection of food fraud and adulteration by food category. J Sci Food Agric 2017;97:3877-3896
2. Cavin, C., et al. Meat vulnerabilities to economic food adulteration require new analytical solutions. Chimia (Aarau) 2018;72:697-703
3. Quail, M.A., et al. A tale of three next generation sequencing platforms: comparison of Ion Torrent, Pacific Biosciences and Illumina MiSeq sequencers. BMC Genomics 2012;13:341