Comparison of in vitro antioxidant activities of malt, hops, worts and lager type beer

摘要

The total antioxidant activities of methanol and water extracts from malt and hops, as well as antioxidant activities of intermediate products withdrawn at different stages of the brewing processes were investigated. Crude extracts from malt and from hops showed strong antioxidant capacities in vitro in two applied systems: with 2.2'-azinobis-(3- ehylbenzothiazoline-6- sulphonic acid) (ABTS), and using linoleic acid -water emulsion. Higher antioxidant activities were gained for methanol extracts,indicating better extraction of the phenolic compounds. The highest antioxidant activity in method using ABTS and myoglobin was recorded for wort after addition of hops. but in the linoleic acid emulsion system, beer after fermentation was superior to other beers in inhibiting linoleic acid oxidation. The differences in antioxidant activities recorded for studied samples were stated, depending on the two applied methods, what suggests the presence of different mechanisms involved in the oxidation reactions in assayed media.