Antioxidant capacity of extracts from amaranth (Amaranthus hypochondriacus L.) seeds or leaves

• We evaluated antioxidant capacity and total phenolics of extracts from amaranth seeds or leaves.
• Antioxidant compounds were extracted by two methods: magnetic stirring and Soxhlet.
• Methanol was better extraction solvent for amaranth seeds and ethanol for leaves.
• Extracts from leaves exhibited more antioxidant capacity than those from seeds.
• Antioxidant capacities of studied extracts are not only due to phenolic compounds.

The effect of extraction method and solvent type on antioxidant capacity and total phenolic content of extracts from amaranth (Amaranthus hypochondriacus L.) seeds or leaves were evaluated. Antioxidant compounds were extracted by two methods: magnetic stirring or Soxhlet. For these two methods, methanol, ethanol, or hexane, were tested as solvents. Antioxidant capacity was determined by inhibition of DPPH· radical. Total phenolics were determined by the phenol Folin–Ciocalteu assay. There was a significant effect (p ≤ 0.05) of extraction method and solvent type on antioxidant capacity and total phenolics of studied extracts. Greatest antioxidant capacities, up to 1070 equiv. of Trolox (mg/100 g dry weight), and total phenolics, up to 619 equiv. of gallic acid (mg/100 g dry weight), were determined in extracts from the Soxhlet extraction method; methanol was a better extraction solvent for amaranth seeds while ethanol was for leaves. In general, extracts from amaranth leaves exhibited more antioxidant capacity than those from seeds. Antioxidant capacities of studied extracts are not only due to phenolics.