Lipid profiling: proving the geographical origin of strawberries (Fragaria × ananassa) using a non-targeted LC-IM-MS approach†

Abstract

The strawberry, a globally traded fruit, is a prime example of how geographical origin has become an important marketing factor. Significant price differences between countries of origin make mislabeling a financially attractive form of food fraud, underlining the need for origin verification. In this context, the development of methods that can unequivocally prove the authenticity, i.e., the declared origin, is an absolute necessity. In this study, a non-targeted lipidomic approach using ion mobility combined with high resolution mass spectrometry was applied to clearly distinguish German strawberries from non-German strawberries. Using linear discriminant analysis (LDA), an accuracy of 90% was achieved. Furthermore, a detailed classification of strawberries from Central Europe (German, Dutch and Polish strawberries) as well as strawberries from Mediterranean regions (Spanish, Greek and Egyptian strawberries) was carried out with a classification accuracy of 74%. To further investigate the classification results, a total of 39 lipids were identified as relevant markers for German, Dutch and Polish strawberries as well as for Spanish, Greek and Egyptian strawberries using MS/MS measurements. A particular difficulty was the fact that the influence of climatic conditions on the metabolome is similar in countries that are geographically close to each other. Overall, the results of this study help to prevent food fraud and to confirm the authenticity of strawberries in terms of their origin.