Biotechnology Letters, Vol.34, No.1, 97-102, 2012
Bioconversion into ethanol of decorticated red sorghum (Sorghum bicolor L. Moench) supplemented with its phenolic extract or spent bran
The effect of extracted phenolics or spent bran added to decorticated red sorghum kernels during fuel ethanol production was studied and compared to maize and whole red and white sorghums. After liquefaction, free amino nitrogen ranged from 65 to 101 mg/l and at the end of saccharification all mashes had approx. 80 g glucose and 2-5 g maltose/100 g meal (dry basis). Saccharified worts were fermented giving 50-90 ml ethanol/l. The lowest fermentation efficiency (76%) was obtained in the white sorghum. Ethanol yields indicate that sorghum bran or its associated phenolics did not significantly affect the efficiency of the sequential steps involved in ethanol production. Red sorghum is a good alternative to maize to produce ethanol and the difference regarding white sorghum and maize was mainly due to endosperm protein structure and composition.