Abstract:

An orthogonal array design was applied to establish the optimum conditions of ethanol concentration, solidto-
liquid ratio, solvent pH, temperature and time for increased yield and purity of anthocyanins from grains of Super Dark
Maize (SDM). The results showed that maximum yield (18.71%) but minimum purity (A550nm/A275nm = 0.10) of anthocyanins
were observed under the conditions of 90%, 1:15 (g/mL), 1, 80 ℃ and 15 h for ethanol concentration, solid-to-liquid ratio, pH,
temperature and and time, respectively. The optimum extraction conditions to achieve maximum yield while increasing the purity of
anthocyanins were 90% ethanol acidified to pH 1.5 as the extraction solvent with a solid-to-liquid ratio of 1:15, 70 ℃ and 15 h.

Key words: dark maize, anthocyanin yield, anthocyanin purity, extraction condition, optimization