Table 2 shows the reducing sugar released after enzymatic
hydrolysis, the remaining reducing sugar after fermentation by
S. cerevisae var. bayanus, as well as sugar consumed for fermentation.
Due to lower release of reducing sugar and high reaction time
(20 h), the use of Liquozyme was rejected for starch liquefaction
and Ternamyl was selected with higher hydrolysate reducing sugar
and shorter reaction time (1 h).
The results indicate that higher enzyme concentration leads to
higher fermentable reducing sugar content. Obviously, the same
conversions could be achieved with lower enzyme concentration,
although requiring longer times. The longer exposure of the enzyme
to high temperatures (85 C for Ternamyl), needed for gelatinization
of the starch granules and to achieve a good susceptibility
to enzyme action could lead to slight enzyme deactivation (Mojovic
et al., 2006).