Authors
Title
Abstract
Ellagic acid (EA) occurs in some plants in its free form, as a glycoside or as an ester. As an ester it occurs in hydrolysable tannins, which include ellagitannins (ET) and gallotannins. On top of the hydrolyzable tannins, the plants also have proanthocyanidins (called proanthocyanidins or non-hydrolysable tannins). The compounds as named above are known for their health promoting properties. Pomegranate fruits and raspberries are the main highly valuable source of tannins, especially of hydrolysable tannins. Pseudo fruits of rose also contain significant quantities thereof. The objective of the present study was to determine the total content of ellagic acid and polymerized proanthocyanins (PP) in pseudo fruits of three rose species: Rosa rugosa (…. and ‘Plowid’ cultivar), Rosa canina, and Rosa pomifera (‘Karpatia’ cultivar) . The total EA content in the solutions after hydrolysis and the content of proanthocyanidin polymers were determined using an ultra performance liquid chromatography (UPLC). It was found that the raw materials analyzed cnstituted a valuable source of condensed and hydrosylable tannins. Higher amounts of ellagic acid had the commonly occurring in Poland rose species, i.e. Rosa rugosa (Japanese rose) (1247.3 µg/g dm) and Rosa canina (1035.5 µg/g dm) compared to the cultivated roses including the ‘Plowid’ cultivar (403.1 µg/g dm). The highest content of proanthocyanidins was determined in the pseudo fruits of ‘Plowid’ cultivar of Rosa rugosa (44716.98 µg/g dm), whereas the lowest content in the wild rose (Rosa canina): 21221.59 µg/g dm.
Keywords
rose, tannins, ellagic acid, proanthocyanidin polymers proanthocyanidin polymers, rose pseudo fruits