Antioxidant activity of cookies supplemented with sugarbeet dietary fiber

The antioxidant activity of cookies prepared by the addition of sugarbeet dietary fibers was investigated in order to estimate their influence on functional characteristics and shelf-life of cookies. Treated fiber (TF) was obtained from sugarbeet by extraction with sulfurous acid (75 degrees C at pH = 5.7 during 60 min) and treatment with hydrogen peroxide (20 g/L H2O2 at pH = 11 during 24 h). The fiber obtained was dried (80 degrees C), ground and sieved. TF was investigated in comparison with commercially available Fibrex (R). The cookies were prepared by the addition of 0, 7, 9 and 11% of sugarbeet dietary fiber as a substitute for wheat flour in the formulation of cookies. The antioxidant properties of cookies were tested every 7 days using a DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity test during 6 weeks of storage at room temperature (23 +/- 1 degrees C). The obtained results indicated that substitution of wheat flour with Fibrex (R) in the formulation of cookies upgraded the antioxidant activity, i.e. the functional characteristics of Fibrex (R)-enriched cookies and could prolong their shelf-life. In contrast, TF did not increase the antioxidant activity of TF-enriched cookies. The better antioxidant activities of Fibrex -enriched cookies could be attributed to the presence of ferulic acid.