There is increasing need for natural food colorants with biofunctional properties. Anthocyanins from black, brown and red sorghums were characterized for composition, color, antioxidant activity and pH stability over time. Only the relatively rare 3-deoxyanthocyanins were detected in sorghum. Sorghum brans had 3-4 times higher anthocyanin contents than the whole grains. The black sorghum had the highest anthocyanin content (average 10,100 mg/kg in bran), while the brown and red sorghum brans ranged from 2,800-4,300 mg/kg. These levels were higher than those reported for most fruits and other cereals. The crude sorghum anthocyanin extracts were more stable to pH than crude anthocyanins from blueberry, red raspberry, and cranberry. Purified sorghum 3-deoxyanthocyanidins were also more stable to pH than purified anthocyanidins and their glycosides. Antioxidant properties of the 3-deoxyanthocyanidins were similar to the anthocyanins. Pigmented sorghums have high levels of unique 3-deoxyanthocyanins which are stable to change in pH and have a good potential as functional natural food pigments.
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