Meeting Abstract - Poster Presentation

Concentration and temperature stability of anthocyanins in black sorghum
A. P. CARDENAS-HINOJOSA (1), L. Njongmeta-Nenge (1), L. Dykes (1), L. Cisneros-Zevallos (1), L. W. Rooney (1)
(1) Texas A&M University, College Station, TX
Cereal Foods World 52:A38

The anthocyanins present in sorghum are the unique 3-deoxyanthocyanins that are more stable to pH changes compared to common anthocyanins from fruits, which render them as potential natural colorants. Concentration and temperature stability of anthocyanins in black sorghum bran were evaluated. Extracts at different concentrations were reconstituted in aqueous ethanol, and the pH was adjusted to 3 using 0.1N HCl. Color change was evaluated for each sample over a four-week period as L*, a*, and b* (CIELAB) color space coordinates. Hue and chroma were also calculated. Thermal stability was also evaluated using aqueous ethanol extracts (pH 3) at –4°C, 4°C, 25°C, and 100°C over 0 h, 2 h, 1 day, and 1 to 4 weeks, and compared with standard red colorants FD&C Red #3 and FD&C Red #40. At different concentrations, the color ranged from orange to dark red; changes in L*, a*, and b* values occurred over time. There were also changes in the L*, a*, and b* values when the aqueous ethanol extracts were exposed at different temperatures over time. Sorghum bran shows potential use as a natural food colorant.