Verification of Geographical Origin by Stable Isotope Analysis
Food fraud has grown enormously in recent years because of two key factors: the complexity of supply chains and consumer demand for high quality foods. These factors have combined to create a situation that is a real challenge for industry.
Our globalized complex supply chains provide food fraudsters with numerous opportunities to adulterate high value food products with cheaper ingredients. Although it is difficult to define one type of food fraud as the most common, it is probable substitution/mislabeling is the single biggest problem. Within this category, we find the issue of mislabeling of products regarding their provenance or geographical origin.
Opportunities for Adulteration
Consumers receive lots of information concerning their food, much of it misleading or diverse. For ‘premium’ products the issue can be greater because they often rely on geographical origin as a factor in their higher value. For instance, they may come from a Protected Designation of Origin (PDO) or a Protected Geographical Indication (PGI), from an emotion-driven priority like local or regional, or, alternatively, from an area that is black-listed.
With the price disparity between premium and ‘conventional’ products growing, there is greater scope for profit in these geographically-based products through adulteration. At the same time, it also provides opportunities for the food industry to secure its production, differentiate in the market and develop a brand to a premium level.
It is important to make a clear differentiation between the assurance of transparency across the supply chain and the actual verification of the authenticity of a product’s provenance. Supply chain management through a system like Transparency-One is essential to provide secure and complete information about the claims made for a product, i.e. where it should come from. This does not, however, serve as evidence of the authenticity of a product, only as a transparent declaration of its provenance. Whether this declaration is genuine can only be answered by analytical verification of its geographical origin.
Today’s technology allows the use of different techniques to provide evidence of the geographical origin verification of a product. Techniques are mostly non-targeted, creating fingerprints or profiles of a product using different analytes, parameters or indices. These variables connect the information hidden in a product to local conditions in the area of production. Among the available techniques, Stable Isotope Analysis has a prominent position for reasons such as:
- The multi-isotope fingerprint (carbon, nitrogen, sulfur, hydrogen and oxygen isotope ratios) contains a wealth of information about the local climate, the soil and the geological background, the plant’s physiology and metabolism, the fertilizers, the animal feed, even to details such as the proximity to the sea, greenhouse production and organic farming
- Stable Isotope Analysis has been used for decades in proving geographical origin claims, having elevated the current knowledge and expertise to high standards for diverse matrices and topic complexity
- Today, it is an affordable testing solution, offered in a strictly commercial way and in versions that are based on the science but converted into a simple service
The use of stable isotopes in the verification of the geographical origin of food led to the creation of isotope databases, collecting data for a certain region, country or many countries. These isotope databases are product-specific. They provide general information of the expected variation of the isotope fingerprint between the given areas. Identifying that databases have certain advantages and disadvantages, it is recommended in many cases to use instead a targeted and specific authentic reference dataset that refers to each case.
This Reference Sample System (RSS) can be used to control the supply chain, to check a suspect source of products or to compare charges. The principle is that usually the question is not “where does it come from” but rather “is this truly from there?”. In order to provide an accurate answer, there is a need for the direct comparison of the tested samples with authentic, specific reference samples from a given area and for a given time period (e.g. harvest year).
A good and functional database needs a lot of data. It also needs to be updated for seasonal and annual variations. However, isotope databases can be a strong tool for quick screening of certain products. The need for reliable authentic samples is significant. The development of a reliable database takes time and costs could be high. As for the need to keep an isotope database up-to-date, experience shows that the seasonal variations of fingerprints due to different conditions could potentially be more significant than geographical variations, especially between neighboring areas.
Reference Sample System (RSS)
The RSS provides high reliability through its multi-component approach. The service includes not only an analysis and its results but also an illustrated way to present the outcome of the testing that can be used in the longer term for monitoring the deviations of a product across time. The outcome is a full service, not just a one-off test. Further, the RSS uses contemporary fingerprints that help to avoid seasonal variations.
Nature does not follow political borders. Isotope fingerprints, like any kind of chemical fingerprint, do not alter between the two sides of country borders or regional boundaries. The verification of geographical origin is a forensic investigation, where scientific evidence is used in order to provide evidence for or against a hypothesis. There is no characteristic fingerprint for Italian tomatoes, German asparagus or salmon from North Atlantic. Nevertheless, comparing isotope fingerprints makes it possible to get to a reasonable conclusion regarding the geographical origin claim of a product and to identify a false declaration based on solid scientific arguments.
During recent years, new versions of food safety standards have included a comprehensive requirement for risk assessment, including food fraud as a major influencing parameter. Companies are required to deliver risk mitigation plans, taking measures against the risk of food fraud in their supplies. Such schemes will often include analytical testing because it removes doubt and dramatically decreases the risk of food fraud incidents, like false declarations of geographical origin.
Furthermore, Stable Isotope Analysis is a powerful tool in a variety of other food authenticity issues. For example: the differentiation between natural and artificial flavorings, the detection of unauthorized food component additions (e.g. sugars in juices, honey and syrups, water in wine and juices, alcohol in wine and spirits etc.), and the identification of animal or plant-derived ingredients. We will cover these aspects in more detail in future articles.
The need to prevent food fraud is now being taken seriously by all stakeholders. Governments and the food industry have awoken to the issues surrounding Country of Origin Labeling as higher value for local and regional foods directly affect the marketplace. Ensuring the geographical origin and labeling of ingredients is correct has therefore become a major factor in maintaining market dominance for these ‘premium’ products. Geographical Origin Verification is a useful tool in protecting these products because it not only helps to reduce fraud in your supply chains, it also benefits your customers and helps to protect your business and the food industry.
For the complete range of SGS services and support visit SGS Food Safety or send an email to us.
Dr. David Psomiadis
Head of lab / Business Development Manager
t: +43 676 39 69442