08.08.2015   Liquid Biofuels: Emergence, Development and

Starchy Biomass

Starch is a polysaccharide composed of glucose units (monomers). This poly­saccharide requires acidic hydrolysis to release the glucose monosaccharide to be fermented by S. cerevisiae yeast to produce 1G ethanol. The starch chemical structure is presented in Fig. 3. Examples of starch-containing plants include corn, potato, cassava, wheat, and barley (Table 4).

Plant

Starch (% m/m)

Protein (% m/m)

Fiber (% m/m)

Others (% m/m)

Corn (flour of grain)

90.1

6.5

0.52

1.99 (lipid)

Cassava (pulp)

83.8

1.5

2.5

0.2 (lipid)

Potato (pulp)

71.5

8.6

5.4

—

Table 4 Chemical composition of corn grain flour (Sandhu et al. 2007), cassava (Charles et al. 2005), and potato (Liu et al. 2007)

Fig. 4 Lignin structure (left) and its precursors (right): (I) p-coumaryl alcohol, (II) coniferyl alcohol, and (III) sinapyl alcohol. Author Silvio Vaz Jr