2.1. Sorghum
Sweet sorghum Rio harvested in October 2006 was kindly provided
by Prof. M. J. Wang (Chinese Academy of Agriculture Engineering,
China). Leaves and husks were stripped from the fresh stalks by
hand and stored in the freezer at −20 °C. Following thawing at
room temperature, the stalks were cut into small particles. To
adjust the moisture content of the sorghum, the chopped particles
were dried in an oven at 80 °C until the desired moisture level was
achieved. Sugar contents of the fresh stalks were (g/100 g sweet
sorghum stalks): glucose, 0.5; fructose, 1.1; sucrose, 15.5, and the
initial moisture content was 71%.