Evolution of ellagitannin content and profile during fruit ripening in Fragaria spp.

Ellagitannins and ellagic acid conjugates are polyphenols significantly present in the human diet, given the content in some fruits, such as berries and in particular strawberries (Fragaria spp.). The first aim of this study was isolation and structural characterisation of casuarictin and 3-O-methyl ellagic acid 3'-O-α-rhamnopyranoside, which were found to be abundant in strawberries and woodland strawberries, along with agrimoniin. The second aim was accurate profiling and quantification of 26 ellagitannins and ellagic acid conjugates in six Fragaria x ananassa cultivars 28 and two Fragaria vesca genotypes, which were analysed in triplicate at 4 different ripening stages. The third aim was to describe the behaviour of this class of polyphenols during fruit ripening from 30 the green stage to over-ripeness. It was shown that there are major qualitative and quantitative differences in the amount and profile of ellagitannins and ellagic acid conjugates in Fragaria x ananassa and Fragaria vesca species, as well as several qualitative differences in some minor ellagitannins in the Fragaria x ananassa cultivars. Genotype is a major factor in defining ellagitannin concentration and patterns in Fragaria spp., and variable behaviour of the genotypes was observed, in the context of a significant drop in ellagitannins during ripening.