The effect of simulated digestion in vitro on bioactivity of wheat bread with Tartary buckwheat flavones addition

The antioxidant activity of bread enriched in an extract from the green parts of buckwheat plant (TBF-Tartary buckwheat flavones) was determined. The bread's quality was slightly decreased when 2.5% TBF was added: however, with an addition of 5% TBF caused a high decrease in the bread's quality. Despite the digestion stage, the content of total phenolic compounds were the lowest in the case of the samples from the control bread (without buckwheat addition). Despite the kinds of bread, the lowest content of total phenolics and flavonoids and the highest phenolic acids content were detected in the fluids after simulated saliva digestion. Despite the digestion stage, the highest antiradical activity, reducing power and ability to inhibition of lipid peroxidation was observed in the samples with a 5% TBF addition. The free radical scavenging activity grew along with the increase of buckwheat preparate addition and in the progress of the in vitro digestion. The maximum of reducing and chelating power in the control sample were observed after simulated saliva digestion, whereas in the case of bread with the TBF addition the highest reducing power was observed after simulated gastric digestion, and maximum of chelating power - after simulated intestinal digestion. (C) 2008 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.