Determination of phenolic compounds and antioxidant capacity in frozen fruits of sour cherry, strawberry, cranberry, blackberry and red currant

Istraživanje je provedeno na zamrznutim plodovima pet vrsta voća (višnja, jagoda, brusnica, kupina, crveni ribiz) od dva distributera s hrvatskog tržišta. Određivani su biološki aktivni spojevi, ukupni fenoli, flavonoidi i antocijani te antioksidativni kapacitet spektrofotometrijskim metodoma. Za određivanje antioksidativnog kapaciteta korištena je FRAP metoda. Dobiveni rezultati pokazuju da je svih pet vrsta voća dobar izvor flavonoida, antocijana te naročito ukupnih fenola. Voće koje se posebno ističe visokom koncentracijom ukupnih fenola i flavonoida je brusnica Distributera1, dok se posebno visoke koncentracije antocijana ističu u plodovima višnje Distributera2. Najviši antioksidativni kapacitet određen je u plodovima kupine Distributera1. Dobiveni rezultati pokazuju da postoji povezanost fenolnih spojeva s antioksidativnim kapacitetom, međutim pojedinačne skupine fenolnih spojeva kao npr. flavonoidi ili antocijani manje doprinose antioksidativnom kapacitetu nego ukupni fenoli. Na temelju koeficijenata korelacije može se zaključiti da postoji sinergistički utjecaj fenolnih spojeva na antioksidativni kapacitet.Five different fruit species from two Croatian distributors (sour cherry, strawberry, cranberry, blackberry, red currant) were investigated and biologically active compounds, total phenolic compounds, flavonoides, anthocyanins, as well as antioxidatic capacity, were determined by spectrophotometric methods. FRAP method was used for determination of antioxidant capacity. Obtained results are showing that all five investigated fruits are a good source of flavonoids, anthocyanins and especially a good source of total phenolic compounds. Fruit with considerably highest concentrations of total phenols and flavonoids is cranberry Distributor 1, while the highest concentrations of anthocyanins was deterimined in sour cherry Distributor 2. The highest antioxidant capacity is determined in blackberry Distributor 1. Obtained results are showing that there is a correlation between the phenolic comounds and the antioxidant capacity. Flavonoids and anthocyanins alone contribute less to antioxidant capacity then total phenolic compounds. Based on the values of correlation coefficients we can coclude that there is a sinergistic effect of phenolic compounds on antioxidant capacity