Ellagic acid and its derivatives in pomegranate (Punica granatum L) from growing site of cultivations

Poznato je da na koncentracije fenolnih spojeva u voću utječu agroekološki uvjeti ali i termin berbe. Stoga je cilj ovog istraživanja bio ispitati utjecaj područja uzgoja i termina berbe na količinu ukupnih fenola (određivano spektrofotometrijski), pojedinačnih fenolnih spojeva, elaginske kiseline i njenih derivata (određivano primjenom HPLC uz UV PDA) u zrnima nara. Također je ispitano postoji li povezanost između koncentracije ukupnih i pojedinačnih fenolnih spojeva te antioksidacijske aktivnosti određivane primjenom FRAP metode. Utvrđeno je da su plodovi nara dobar izvor fenolnih spojeva neovisno o području uzgoja i terminu berbe. Značajna skupina spojeva određena u sjemenkama nara su elaginska kiselina i derivati elaginske kiseline (punikalagin 1 i 2 ). U svim ispitivanim ekstraktima plodova nara određena je značajna antioksidacijska aktivnost. Na temelju regresijske analize dobra linearna povezanost antioksidacijske aktivnosti utvrđena je samo s koncentracijom ukupnih fenola, dok je istovremeno utvrđeno da pojedinačni fenolni spojevi slabo doprinose antioksidacijskoj aktivnosti (r < 0,5).It is known that the concentration of phenolic compounds in fruits is affected by agroecological factors and with date of harvesting. Therefore, the goal of this research was to examine the influence of growing site of cultivations as well as the influence of date of harvesting on the amount of total phenols (determined spectrophotometrically), individual phenolic compounds, ellagic acid and its derivatives (determined using HPLC with UV PDA) in pomegranate seeds. It is also researched is there a correlation between the concentrations of total and individual phenolic and antioxidant activity determined using FRAP methods. It was found that the pomegranate is a good source of phenolic compounds, regardless of growing site of cultivations and date of harvesting. A significant group of compounds determined in the pomegranate seeds are ellagic acid and its derivatives (punicalagins 1 and 2). In all investigated pomegranate seeds extract was determined a significant antioxidant activity. Based on regression analysis, a good linear correlation of antioxidant activity was found only with the of total phenolics, while it was found that individual phenolic compounds were not remarkable contribute to the antioxidant activity (r < 0.5)