After running the control experiments, we examined the fermentation
of SM that had been hydrolyzed by -galactosidase.
Preliminary experiments to determine the concentration of soybean
molasses to be enzymatically hydrolyzed were performed to
provide better ethanol yields and residual sugar concentrations.
The kinetic profiles of alcoholic fermentation in relation to substrate
consumption, the ethanol production and a number of cell
and experimental design parameters were also determined. The
CCD was used to evaluate the influence of the enzyme concentration
and the temperature of fermentation on the parameters of
interest (Y2, P and RS). The enzymatic hydrolysis was performed at
pH 4.5 and 55 ◦C with 250 g/L of soybean molasses, as determined
by the preliminary experiments. After 10 h of enzymatic hydrolysis,
the samples were inoculated in the same fermentation reactor with
a 35 g/L initial concentration of inoculum at pH 4.5 and a temperature
of 35
±
1 ◦C. The amount of enzyme used (X1) in the CCD ranged
from 0.021 to 0.079% based on the weight of the substrate, and temperature
(X2) ranged from 49.3 to 60.7 ◦C. An alpha orthogonality
of 1.147 was used in planning. The ranges of enzyme concentration
and temperature adopted in the CCD were selected according to
information from the manufacturer of the enzyme.