ANTIRADICAL ACTIVITY OF DIFFERENT BARLEY VARIETIES AND MALT TYPES

Cereal grains have long been thought to be less important sources of antioxidants than fruits and vegetables although they contain many antioxidants and are major dietary components worldwide. The aim of the current research was to study and compare an antioxidant activity (AOA) and total phenolic content (TPC) of different barley varieties and malt types as well as to evaluate possible interconnection between TPC and AOA of barley and malt samples. The research was carried out on four lines of hull-less barley '3528'; ' L-400'; ' 3475'; '3537' and one variety of flaky barley 'Klass' grains, which were cultivated in Latvia in 2010, and their corresponding malt. Commercial sorts of malt -Pilsener, Munich, Caramel and Dark were used in the research to compare with the malt produced in the laboratory scale. The antioxidant potential of barley and their products is analyzed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. Total phenolic content of barley and malt samples was determined according to the Folin-Ciocalteu spectrophotometric methods. The values of DPPH radical scavenging activity for 5 barley samples ranged from 4.57 to 5.89 mu mol TE g(-1) DW. The total amount of phenols ranged from 1.96 to 2.43 mg GAE g(-1) DW for unprocessed barley samples and from 2.5 to 3.4 mg GAE g(-1) DW for their corresponding malt. TPC of malt commercial sort ranged from 3.5 to 6.7 GAE g(-1) DW. The increase of TPC for commercial malts is strongly related with Maillard reaction products.