Introduction
High oil prices stimulated interest in bioethanol as a
potential liquid fuel for transportation (Margaritis and
Pratima, 1983). Bioethanol is currently produced using
carbohydrate sources in many countries. Common
feedstocks for ethanol production are sugarcane, cassava,
corn grain, and many other agricultural raw materials
rich in fermentable carbohydrates. These feedstocks are
then chemically converted to yield fermentable sugars
(Lin and Tanaka, 2006). Corn, sorghum, Jerusalem
artichoke, potato, and lignocellulosic biomass are sources
of feedstock with great potential for ethanol production
(Azhar and Hamdy, 2003).
Mainstream raw materials such as sugarcane, cassava,
and corn grain have limited harvest times and are rarely
available for year round production. Nonconventional
feedstocks such as sweet sorghum and Jerusalem artichoke
can diversify raw materials and extend production times
for the bioethanol industry (Walker, 2010). Of these