文摘
Beers are a source of dietary flavonoids; however, there exist differences in composition, alcoholconcentration, and beneficial activities. To characterize these differences, three kinds of lager beerof habitual consumption in Spain, dark, blond, and alcohol-free, were assayed for total phenolic content,antioxidant activity, superoxide and hydroxyl radical scavenging activities, and in vitro inhibitory effecton DNA oxidative damage. Furthermore, their melanoidin content and correlation with antioxidantactivity were evaluated. Dark beer contained the highest total phenolic (489 ± 52 mg/L) and melanoidin(1.49 ± 0.02 g/L) contents with a 2-fold difference observed when compared to the alcohol-free beer.For the three kinds of beer, the antioxidant activity measured as N,N-dimethyl-p-phenylenediaminedihydrochloride concentration was strongly correlated with the total polyphenol content (R2 = 0.91102,p < 0.005) and with the melanoidin content (R2 = 0.7999, p < 0.05). The results support a positiveeffect of beers on the protection of DNA oxidative damage, by decreasing the deoxyribose degradation,DNA scission (measured by electrophoresis), and inhibition of 8-hydroxydeoxyguanosine (8-OH-dG)formation. Furthermore, a correlation between the total melanoidin content (R2 = 0.7309, p < 0.01)and inhibition of 8-OH-dG was observed.Keywords: Beer; antioxidant; phenolics; melanoidins, deoxyribose, 8-hydroxydeoxyguanosine(8-OHdG)