Influence of the extraction procedure on the antioxidative activity of lentil seed extracts in a beta-carotene-linoleate model system

Phenolic compounds were extracted from lentil seeds using three solvent sys tems: 80% (v/v) acetone. 80% (v/v) methanol, and 80% (v/v) ethanol. Each ex tract was subsequently separated into two fractions by chromatoghraphy on a column with Toyo Pearl HW-40 using water (fraction I) and methanol (fracti on II) for elution. Antioxidative activity of extracts and their respective fractions were examined in a beta -carotene-linoleate model system. All th ree extracts exhibited similar antioxidant activity. Considering the level of phenolic compounds in extracts it seems that phenolic compounds from the acetone extract were less active than those from either the methanolic and ethanolic ones. Because the content of phenolics was about 16-fold lower i n fraction I of the methanolic and ethanolic extracts compared to fraction ii, the phenolics in fraction I of the methanol and ethanol extracts from l entil seeds are much more active than these in fraction II. A stronger anti oxidant activity of fraction I from the acetone extract compared to the cru de acetone extract was observed during the latter incubation stage. The rea son was a relatively high level of phenolic compounds in this fraction. UV spectra confirmed that the phenolic compounds from the acetone extract were different compared to methanolic and ethanolic extracts.