TERROIR DIFFERENTIATION OF LAMBRUSCO PDO WINES BY STRONTIUM ISOTOPIC SIGNATURE

The interest of consumers, as well as of producers, toward origin and quality of food has increased over the last years. As regards the oenological field, the quality of wine is in many cases related to the concept of terroir (history, geographical origin, typical raw materials and methods, ecc.). In this context, the assessment of the link between the territory of origin and the food product by means of analytical indicators represents a challenging target, useful for the valorization of the product itself. Among the different indicators used for geographical traceability studies, the 87Sr/86Sr isotopic ratio (Sr-I.R.), has provided excellent results for different types of food. The present research is part of a project dealing with the development of authenticity and geographical traceability models of PDO Italian wines [1], with particular reference on Lambrusco wines, which are one of the main typical products of the Modena district. The possibility of obtaining reliable traceability models is mainly linked to the capability of monitoring the considered indicator in a representative set of investigated matrices: mainly soil and wines. Thanks to the collaboration with Consorzio Marchio Storico dei Lambruschi Modenesi, it has been possible to measure the Sr-I.R. on a statistically representative set of Lambrusco wines, commercially available and produced in 2010, 2011 and 2012. Furthermore, Sr-I.R. values of wines were compared with the Sr-isotopic ranges of Modena soils, with the aim to verify and establish a link with the respective territory of origin. The selection of representative, informative and different soil samples of the Modena district was accomplished in a previous work by means of Design of Experiment techniques, in order to ensure a sustainable and rational mapping of the investigated geographical area, taking into account properties related to geological features and production variables (grape varietals and produced quantities) [2]. Finally, the Sr-I.R. was also determined on vine branches, collected in proximity of each soil sampling point, since previous researches highlighted an improvement of the correlation with food and a better discriminating power, when considering branches instead of soil [3].