Influence of different poliphenolic compounds present in aronia on its antiradical activity

U ovom radu istraţivana je antiradikalna aktivnost razliĉitih skupina polifenolnih spojeva iz aronije. Ekstrahirane su tri frakcije polifenolnih spojeva. Prva je bila obogaćena flavonolima i fenolnim kiselinama aronije, druga antocijaninima, a treća netopljivim polifenolima i proantocijaninima. Antiradikalna aktivnost frakcija odreĊena je pomoću DPPH metode te je reakcija hvatanja slobodnih DPPH radikala promatrana u vremenu od 300 minuta. OdreĊena je antiradikalna aktivnost pojedinih skupina polifenola raĉunanjem EC50 vrijednosti i ARP vrijednosti („antiradical power“=1/EC50). U aroniji je pronaĊeno najviše netopljivih polifenola i proantocijanidina (8973 mg/kg svjeţeg voća), zatim slijede antocijanini (2526 mg/kg svjeţeg voća), te flavonoli i fenolne kiseline (1029 mg/kg svjeţeg voća). U ukupnoj antiradikalnoj aktivnosti najveći udio zauzimaju antocijanini (52.5 %), a slijede netopljivi polifenoli i proantocijanidini (34.7%) te flavonoli i fenolne kiseline (12.8 %). Sve skupine polifenola inhibirale su slobodne radikale kroz duţi vremenski period (ovisno o koncentraciji). U reakciji slobodnih radikala s polifenolima aronije primijećena je bifazna reakcija, s periodom u kojem se inhibiranje DPPH radikala odvija brzo, te period u kojem je inhibicija usporena.In this thesis the antiradical activity of different groups of polyphenolic compounds from aronia was investigated. Three fractions of polyphenolic compounds were extracted. The first was enriched with flavonols and phenolic acids from aronia, the second with antocyanins, and the third with insoluble polyphenols and proantocyanins. The antiradical activity of different fractions was determined using the DPPH method and the reaction of capturing free DPPH radicals was observed over a period of 300 minutes. The antiradical activity of individual groups of polyphenols was determined by calculations EC50 values and ARP values („antiradical power“=1/EC50). In aronia, insoluble polyphenols and proantocyanidins were present in the largest amount (8973 mg/kg fresh fruit), followed by antocyanins (2526 mg/kg fresh fruit), flavonols and phenolic acids (1029 mg/kg fresh fruit). In the total antiradical activity, antocyanins occupied the largest share (52.5%), followed by insoluble polyphenols and proantocyanidins (34.7%), and flavonols and phenolic acids (12.8%). All groups of polyphenols inhibited free radicals over a long period of time (depending on concentration). In the reaction of free radicals and aronia polyphenols biphase reaction was observed, with a period in which inhibition of DPPH radicals occured rapidly, and the period in which the inhibition was retarded