A black, high anthocyanin sorghum variety (Tx430) grown in several environments was analyzed for anthocyanins by spec-trophotometric and HPLC methods. The samples were also analyzed for antioxidant activity using the 2,20-azinobis (3-ethyl-benzothiaziline-6-sulfonic acid) method. Two extracting solvents, 1% HCl in methanol and 70% aqueous acetone, were compared. Sorghum brans had three to four times higher anthocyanin contents than the whole grains. The brans were a good source of anthocyanin (4.0–9.8 mg luteolinidin equivalents/g) compared to pigmented fruits and vegetables (0.2–10 mg/g), fresh weight basis. Acidified methanol extracted the anthocyanins better than aqueous acetone. Luteolinidin and apigeninidin accounted for about 50%of the anthocyanins in the black sorghums. The sorghum grains and their brans had high antioxidant activity (52–400lmol TE/g)compared to other cereals (<0.1–34 mg TE/g). Black sorghum should be useful in food and other applications, because it is avaluable source of anthocyanins with good antioxidant activity.
Read the full article here. (article by Joseph M. Awika, Lloyd W. Rooney, Ralph D. Waniska)