According to Soumalainen and Lehtonen (25), the type of
inoculum and the fermentation conditions may interfere with
the formation of aromatic substances, and may have influence
on the production of other substances such as sulphur and
phenolic compounds.
During the production of “cachaça”, some conditions should
be observed in order to obtain a fine quality product, with good
aroma and flavour. The spirit should have harmonious
proportions of non-alcoholic components, as established by
the Brazilian Legislation (4,5).
The content of acetaldehyde, which is the main aldehyde
found in “cachaça”, ranged from 3.07 to 43.76 mg. 100 mL-1 of
anhydrous alcohol (Fig. 1). The legislation allows a maximum
value of 30 mg .100 mL-1 a.a. The highest values were seen in
strain Pa1, which were almost 50% above the legal acetaldehyde
limit in the 1st cycle. The strains Db and Sc also showed an
aldehyde production higher than the permitted values in the 1st
and 10th cycles, respectively. Acetaldehyde levels were within
the admissible range in the other cycles. Aldehydes are
important for aroma and taste of alcoholic beverages (18), but
high concentrations may be toxic to humans, since these are
considered to be responsible for the disagreeable effects after
drinking too much. It is thought that acetaldehyde-rich
“cachaças” are originated in distilleries that do not separate the
head fraction products during the distillation process (7).
Acetaldehyde production by strains Pa1 and Db, in the first
fermentation cycle; Pa2 and Db in the ninth, and Sc in the tenth,
suggest that the levels of acetaldehyde depend on the yeast
strain used as inoculum, and also on the conditions in which the
fermentation processes and distillation have been carried out.
This is supported by the fact that the fractions were separated as
recommended in order to obtain a good quality beverage.