PHENOLIC COMPOUND OF BENIN'S RED SORGHUM AND THEIR ANTIOXIDANT PROPERTIES

The antioxidant activities and phenolic content of various organs (grain, stalk and foliar sheath) of the red sorghum, a tinctorial and medicinal plant of Benin, were determined. The total phenolic content, determined according to the Folin-Ciocalteu method, varied from 19.8 to 233.5 mg/g of dry product whereas anthocyanin content expressed as mg of malvidin equivalents per g of sample (dry weight basis) lies between 28 and 115% of anthocyanin (monomeric form) contained in the grain against 70% and 50%, respectively, for the foliar sheath and the stalk. Antioxidant activity of aqueous ethanolic extracts compared with aqueous extracts, evaluated according to the DPPH method, showed a higher antioxidant activity of aqueous ethanolic extracts. Moreover, all of those samples also contained higher levels of phenolic compounds. Thus, the correlation between total phenolics and antioxidative activities of extracts has been noted. Also, the presence of organic solvent favored the extraction of more bioactive compounds from vegetables materials.