and 60 C [26]. However, approximately 95e96% conversion of
starch only could be achieved during a saccharification period
of 48 h. Several workers have reported on the reduction in
saccharification time by various approaches like simultaneous
use of glucoamylase and pullulanase, glucoamylase
and isoamylase and higher levels of acid amylase with lower
levels of glucoamylase [27e29]. The improved enzyme, Spezyme
was found to have a maximum pH of 5.5 and could be
reduced to 4.5 for the Stargen process at room temperature
(30 1 C) with less cost on acids for pH adjustment. It was
found that after an initial thinning time of 30 min, the liquefied
cassava starch was saccharified to glucose with a high
percentage conversion at room temperature (98.3%) using low
levels of Stargen [100 mg or 45.6 GSHU (Granular Starch
Hydrolyzing Units) for a 10% starch slurry]. Dias and Panchal
[30] reported that in starch liquefaction at near neutral pHs by
bacterial amylases, the chances of maltulose precursor
formation from isomerisation of reducing end glucose to
fructose were more, leading to lower percentage conversion to
glucose at the saccharification stage. Unlike most other aamylases,
Spezyme was found to have an optimum pH of 5.5,
which might have resulted in a high saccharification rate in
our study. Simultaneous saccharification and fermentation
(SSF) was possible using Stargen and yeast as the operating
temperature was 30 1 C. We found that the SSF process
could be completed in 48 h and there was no specific advantage
of conducting the Stargen-aided saccharification first,
followed by yeast fermentation of glucose to ethanol for 48 h.
Several workers have reported that the major advantage of
SSF is the rapid channeling of glucose for ethanol production