Source: International Atomic Energy Agency – IAEA
Every element around us has its own chemical identity. This identity is based on its atomic composition, which consists of neutrons, protons, and electrons. Atoms with the same number of protons but different number of neutrons are called isotopes – these can help scientists to determine if a product is genuine.
Stable isotope ratios in food can vary because of different factors, such as: when, where, and under what environmental conditions the food was produced. For example, stable carbon isotope ratios of tomatoes from Northern Europe grown in a winter greenhouse will vary from the carbon isotope ratios of soil grown tomatoes, harvested in summer in South America.
Stable isotopes are measured using specialized equipment, that can detect the very small differences in the ratios of their heavy and light forms. This information can be used to detect the origin of food. Stable isotope ratios are like nature’s ‘fingerprints’ or signatures on food. This hidden evidence can provide information on whether the foods we are buying consist of the authentic ingredients described on the label or have been falsified. By tracing these isotopic fingerprints, scientists can also track the geographical or botanical provenance of food.
Isotopes also allow to detect the adulteration, or complete substitution, of food with cheap ingredients that have identical chemical structures, but different isotopic signatures. For example, synthetic flavors instead of natural; high fructose corn syrup in honey; or orange juice made from concentrate instead of freshly squeezed.