We investigated, if variety of idustrial hemp affects the content of total phenolic compounds, flavonoids and its subgropus, and antioxidative potential (AOP) of the extracts, from defatted hemp seeds, prepaired by solvent extraction in 70 % (v/v) ethanol. We determined the AOP by DPPH• and O2•⠒ radical scavenging assays and by β-carotene bleaching assay in emulsion of linoleic acid in water. Hemp variety affected the total phenolic, total flavonoid and its subgroups (flavones, flavonoles, flavonones and dihydroflavonoles) content, and the AOP of the extracts. The highest content of phenolic compounds had Kompolti hibrid TC and Monoica varieties. Tiborszallasi had the highest content of flavonoids and its subgroups and also the highest AOP determined by DPPH• scavenging assay. Kompolti hibrid TC had the highest AOP determined by O2•⠒ radical scavenging assay. The type of extraction solvent and its concentration had a big impact on extraction yeld and the AOP. The most efficient solvent for extraction of total phenolics and flavonoids was 70 % acetone. Considering three ethanol concentrations (50 %, 70 % and 90 %), 70 % ethanol was the most efficient for extraction of phenolic compounds, 70 % and 90 % ethanol was the most efficient for extraction of flavonoid compounds. Prolonged extraction time didn't increase the content of total phenolics, but it increased the content of flavonoids and flavonoid subgroups and the AOP. Heat treatment of defatted seeds at 120 °C increased extraction yield of total phenolic and flavonoid content, while longer heat treatment didn't. Heat treatment had a positive impact on AOP of the extracts.
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