Is it really Regiokorn bread? Strontium isotopes can tell us
The growing interest in local and high-quality products makes it increasingly necessary to have scientific tools capable of verifying their authenticity and protecting both consumers and producers from fraud. As demonstrated by previous studies, the strontium isotopic ratio is a very promising marker of origin, as it reflects the geo-lithological signature of the region where agri-food products originate. While tracing the origin of raw or semi-processed materials can be relatively straightforward, verifying the authenticity of processed products, such as bread, is far more complex.
A new study, carried out through the collaboration between Eco Research and the Laimburg Research Centre, addressed this challenge by focusing on South Tyrol’s “Regiokorn” bread — a bread produced in South Tyrol with at least 75% local flour from the Regiokorn supply chain.
The analytical part of the study was conducted at Eco Research laboratories, working on four typical South Tyrolean bread types and their individual ingredients (flour, water, salt, and yeast).
The results show that the isotopic fingerprint of the bread cannot be directly linked to that of the Regiokorn flour used but depends on the combination of all ingredients. However, knowing the recipe and the isotopic signature of each component allows for a reliable prediction of the expected bread value, which can then be compared with the measured one. In addition, applying a dynamic mathematical model to the data enables the detection of any non-compliance with a high degree of confidence — for instance, if the Regiokorn flour content is below the quality standard threshold.
This study opens new perspectives for controlling and safeguarding the authenticity of regional agri-food products.
A B S T R A C T
Regional niche products are increasingly sought after by consumers but also prone to food fraud. South Tyrolean cereals are mostly consumed as traditional bread which must contain a minimum of 75 % regional flour to be marketed under the “Regiokorn” seal. Four typical bread types were prepared and their Sr isotopic ratio and content together with all used ingredients was analyzed. The overall strontium pool of bread is not governed by flour alone, but by all added ingredients (flour, water, salt and yeast), making it impossible to define a clear-cut 87Sr/86Sr window for Regiokorn bread. Nevertheless, the analysis of all ingredients and the application of a mixing model allow for the prediction of a theoretical 87Sr/86Sr value. A statistical error propagation method was employed to establish 95 % confidence intervals that react dynamically to the type and ratio of ingredients. This would enable to detect fraudulent adulterations with a high likelihood.