Determination of bioactive compounds and antioxidant potential of pomegranate peel and arils (Punica granatum L.)

Cilj ovog istraživanja bio je ispitati maseni udio ukupnih fenola, monomernih antocijana i antioksidacijski kapacitet u zrnima i kori nara (Punica granatum L.) ubranih na 11 različitih lokacija na području Hercegovine u dva termina berbe. Maseni udjeli ukupnih fenola (UF) i antocijana su određivani spektrofotometrijski, dok je antioksidacijski kapacitet (AOC) određen primjenom FRAP i DPPH metoda. Maseni udjeli UF u zrnima nara plodova ubranih na svim lokacijama bili su veći u prvom terminu berbe. Određeni su u rasponu od 302,23 do 586,94 mg GAE/100g nara. Istovremeno je utvrđeno da su maseni udjeli antocijana bili veći u zrnima plodova iz drugog termina berbe, a iznosili su od 313,95 do 616,62 mg Cy- 3-Glc. Kora nara izrazito je bogat izvor fenolnih spojeva. Koncentracije UF u uzorcima iz drugog termina iznosile su od 5766,44 do 10257,72 mg GAE/100g, te je utvrđeno da je u kori koncentracija UF bila u svim uzorcima 22 do 23 puta veća u usporedbi sa zrnima nara. U svim uzorcima određen je visok AOC, a prema regresionoj analizi utvrđena je bolja povezanost između koncentracija UF i AOC nego antocijana i AOC.The aim of this research was to examine the mass concentration of total phenolics, monomeric anthocyanins and antioxidant capacity in pomegranate (Punica granatum L.) arils and peel samples collected at 11 different locations in Herzegovina during two period of harvest. Concentrations of total phenolics (TP) and anthocyanins were determined by spectrophotometric methods, while the antioxidant capacity (AOC) by the FRAP and DPPH methods. TP concentrations in pomegranate arils from all the locations were higher in the first period of harvest, and the content ranged from 302.23 to 586.94 mg GAE/100g pomegranate. At the same time, concentrations of anthocyanins were higher in aril samples harvested in the second term, and ranged from 313.95 to 616.62 mg of Cy-3-Glc. Pomegranate peel is an extremely rich source of phenolic compounds. TP concentration in samples from the second term ranged from 5766.44 to 10257.72 mg GAE/100g, and has beed found that the TP concentration in all peel samples was about 22 times higher compared with pomegranate arils. All the collected samples exhibit very high AOC, but based on regression analysis, higher correlation has beed found between the concentration of TP and AOC than anthocyanins and AOC