Antioxidant activity of model solutions of phenolic compounds with the addition of sucrose

U radu je ispitivana antioksidativna aktivnost modelnih otopina fenolnih tvari s dodatkom saharoze te međusobni utjecaj fenolnih tvari na antioksidativnu aktivnost odnosno sinergijski učinak. Fenolne tvari koje su ispitivane su katehin, kvercetin i galna kiselina te njihove kombinacije. Za određivanje antioksidativne aktivnosti primijenjene su ABTS, DPPH i FRAP metode. Navedenim metodama utvrđeno je da otopina katehina, kvercetina i galne kiseline s dodatkom saharoze ima najveću antioksidativnu aktivnost. Najmanju antioksidativnu aktivnost imaju uzorci pojedinačnih fenolnih tvari. ABTS i DPPH metodom najmanju antioksidativnu aktivnost ima otopina katehin. Najmanju antioksidativnu aktivnost FRAP metodom ima otopina galne kiseline. Sinergijski učinci kod ABTS, DPPH i FRAP metode različiti su za različite uzorke.The subject of this work was evaluation of antioxidant activity of model solutions of phenolic compounds with addition of sucrose and mutual influence of phenolic substances on an antioxidant activity i.e. synergistic effect. Phenolic compounds which have been tested were catechin, quercetin, gallic acid and their combinations. ABTS, DPPH and FRAP methods have been applied to determine antioxidant activity. Using ABTS, DPPH and FRAP methods it has been found that solution of catechin, quercetin and gallic acid with addition of sucrose had the highest antioxidant activity. Samples of single phenolic substances have the lowest antioxidant activity. According to the results obtained via the ABTS and DPPH methods, the solution of catechin has the lowest antioxidant activity. According the results obtained via the FRAP method, the solution of gallic acid has the lowest antioxidant activity. Synergistic effects of ABTS, DPPH and FRAP methods have been different for different samples