Determination of Total Polyphenolic Content, Total Flavonoids Content and Antioxidant Activity of Commercially Available Beers Produced by Croatian Industrial and Craft Breweries

Pivo je jedno od najčešće konzumiranih alkoholnih pića, koje ima i nutritivnu vrijednost zbog svog sastava koji uključuje minerale, organske kiseline, vitamine, proteine te različite skupine polifenola. Polifenoli u pivu najvećim dijelom potječu od slada i hmelja. Polifenolnim spojevima, posebice flavonoidima, pripisuje se snažan antioksidacijski učinak te blagotvoran utjecaj na zdravlja čovjeka. Osim antioksidacijskog učinka, polifenoli imaju važnu ulogu u formiranju okusa, boje i gorčine piva, ali imaju i negativan utjecaj na stabilnost piva. Cilj ovog istraživanja bio je odrediti udjele ukupnih polifenola i flavonoida te antioksidacijske aktivnosti 30 uzoraka hrvatskih komercijalno dostupnih industrijskih (15 uzoraka) i zanatskih (15 uzoraka) piva. Koncentracije ukupnih polifenola kretale su se u rasponu od 76,57 mg/L do 382,31 mg/L, dok su se koncentracije ukupnih flavonoida kretale u rasponu od 33,69 mgCTE/L do 180,36 mgCTE/L. Veće koncentracije ukupnih polifenola i ukupnih flavonoida zabilježene su u pivima zanatskih pivovara. Rezultati određivanja antioksidacijske aktivnosti pokazali su da su uzorci piva uspjeli inhibirati 57,82 do 79,86 % DPPH. Usporedbom svih svijetlih i tamnih piva vidljivo je kako su koncentracije ukupnih polifenola i flavonoida te antioksidacijska aktivnost veći u uzorcima tamnih piva.composition which includes minerals, organic acids, vitamins, proteins and various groups of polyphenols. The polyphenols in beer come mostly from malt and hops. Polyphenolic compounds, especially flavonoids, are attributed a strong antioxidant effect and a beneficial effect on human health. In addition to antioxidant effect, polyphenols play an important role in the formation of taste, color and bitterness of beer, but they also have a negative impact on the stability of beer. The aim of this study is to determine the total polyphenols, flavonoids and antioxidant activity of 30 samples of Croatian commercially available industiral (15 samples) and craft (15 samples) beers. Concentrations of total polyphenols ranged from 76,57 mg/L to 382,31 mg/L, while concentrations of total flavonoid ranged from 33,69 mgCTE/L to 180,36 mgCTE/L. Higher concentrations of total polyphenols and total flavonoids were recorded in craft breweries. The results of the determination of antioxidant activity showed that the beer samples were able to inhibit 57,82 to 79,86 % of DPPH. A comparison of all light and dark beers shows that the concentrations of total polyphenols, flavonoids and antioxidant activity are higher in dark beers samples