Stable isotope ratio analysis of different European raspberries, blackberries, blueberries, currants and strawberries.

To date the stable isotope ratios of berries have never been extensively explored. In this work the H, C, N and O isotopic ratios of 190 samples of different soft fruits (strawberries, raspberries, blueberries, blackberries and currants) produced in a northern Italian region and at two sites in Romania and Poland collected over three harvest years are presented and discussed. The different soft fruits showed a typical range for one or more isotopic parameters that can be used to verify the authenticity of the fruit composition declared on the label. The δC and δN of pulp and the δO of juice can be considered effective tools for identifying the different geographical origin of fruit. A significant effect of crop cover on juice δO and fertilisation practices on pulp δN was demonstrated and must be considered with attention when evaluating data.