Abstract: Free and bound phenolic extracts were obtained from eight varieties of barley and corresponding malts. Their components were analyzed and their antioxidant activities were evaluated. The results showed significant differences in the types and amounts of phenolics before and after malting for each barley variety. The total phenolic content of barley was significantly increased after malting (P < 0.05). Among the eight varieties, Hindmarsh displayed the highest percentage increase in total phenolics as well as free gallic acid, vanillin and ferulic acid, and the contents of feculic acid and orientin were increased significantly after malting; Metcalf had the highest percentage increase in bound ferulic acid and orientin. The results of antioxidant assay in vitro showed that the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and oxygen radical absorbance capacity were increased after malting for all the varieties, among which the free phenolics of Scope malt had the strongest DPPH radical scavenging capacity, while the bound phenolics of Baudin malt had the highest oxygen radical absorbance capacity (ORAC) value.

Key words: malt phenolic compounds, antioxidant activity, principal component analysis, high performance liquid chromatography