3.3.3.1. Higher alcohols. The pulp of unfermented beans contained little
higher alcohols but their concentration increased about 12 fold during
fermentations in the absence or presence of nisin + lysozyme
(Fig. 6a). The main higher alcohols found in fermenting pulps were
2-methyl-1-butanol (approx. 76%, and 83% of total higher alcohols),
phenylethyl alcohol (approx. 13.6% and 9% of total) and isoamyl alcohol
(6.5% and 5%). The data in parenthesis are the relative amounts at the
end of fermentation in the absence and presence of nisin + lysozyme,
respectively. Low amounts of higher alcohols were detected in the
nibs before fermentation. These increased about 5 fold throughout fermentation
before decreasing during drying and roasting (Fig. 6b).
Phenylethyl alcohol (69–70% of total higher alcohols), isoamyl alcohol
(16–17%) and 2-methyl-1-butanol (8–9%) were the three main alcohols
found in the nibs with the relative values given being the amounts after
roasting. There were no statistically significant differences between the
concentrations of these alcohols in the pulps or nibs for fermentations in
the presence or absence of nisin + lysozyme.