3.3. Ethanol production
The volume and ethanol concentration of the fractions collected
during the distillation of the fermented broths are shown in Table
3. As expected, the body fractions presented the largest volumes
among the three fractions. The ethanol concentrations were higher
for the head and body fractions. Ethanol production for the series
of experiments with juice diluted to 8–10 Bx and complemented
with molasses up to 12 Bx are shown in Table 3. In the case of
juice diluted to 8 Bx and supplemented with molasses up to
12 Bx, the fermentations with different yeast ratios showed no
significant differences. With the juice diluted to 10 Bx, it was possible
to observe a positive effect on ethanol production by the use
of Saccharomyces in the yeast mixture or alone. Statistical analysis
resulted in two groups. One group with higher ethanol production
was obtained by the use of a 25% Cicy-Ki and 75% Saccharomyces
ratio or Saccharomyces alone. The other group was a low ethanol
production formed by the treatments with ratios of 50% Saccharomyces
or lower and Cicy-Ki alone. This indicates that the use of
Cicy-Ki is not necessary to improve ethanol production. When
the yeast Saccharomyces was used alone, sugar consumption was
slower at first; however, after 24 h of fermentation, consumption
was rapid, indicating that Saccharomyces has a longer adaptation
phase than Cicy-Ki, when it is used to ferment henequen juice. This
behavior was also reported in studies carried out during the isolation
of different yeasts from the henequen plant (Tzec-Gamboa,
2006). Cicy-Ki has a shorter adaptation phase because it is autochthonous
to the henequen plant and is already adapted to the
environment.