Having determined the optimal hydrolysis and fermentation
times for SM, an experimental design was conducted to determine
how the fermentation yield of SM, amount of residual sugar and
the ethanol productivity were affected by the amount of enzyme,
and the temperature used during the hydrolysis (Table 6).
The equations of the empirical model adjusted to the ethanol
yield (Y2), concentration of residual sugar (RS) and ethanol productivity
(P) using 250 g/L of soybean molasses as a function of
significant variables are presented in Eqs. (4)–(6), respectively.
The correlation coefficientes (R2) obtained after adjustment were
0.992 for the ethanol yield, 0.995 for the concentration of residual
sugar and 0.992 for the ethanol productivity, indicating that
the proposed empirical equations faithfully reproduces the results
obtained experimentally.