Bread obtained from wheat flour was digested in in vitro conditions. Changes of content of total phenolic compounds, flavonoids and phenolic acids released during in vitro digestion, determination of their ability to free radical scavenge, metal – chelating ability, reducing power and ability to inhibition of lipid peroxidation were evaluated. During the in vitro digestion the content of total phenolics and flavonoids was increased from 0.34 to 0.62 mg/ml and from 0.13 to 0.21 mg/ml, respectively. The highest content of phenolic acids (174.45 μg/ml) was obtained in fluid after simulated saliva digestion. Ability of DPPH• radical scavenging was increased from 9.8% (after simulated saliva digestion) to 19.6% (after simulated intestinal fluid digestion), whereas reducing power decreased during in vitro digestion. Similar relationship was obtained in the study of metal-chelating ability, which was decrease from 51.2% (after I stage) to 22.3% (after III stage). The highest ability of lipid peroxidation inhibition was obtained in sample after simulated intestinal fluid digestion (72.69%). Antiradical activity was correlated with total phenolic compounds content. Significant correlations between total flavonoids content and ability to inhibition of lipid peroxidation and with phenolic acids content and metal-chelating ability was found.
wheat bread, antioxidant activity, polyphenols, in vitro digestion