Improved Fermentation of Cocoa Beans with Enhanced Aroma Profiles.

The cocoa (Theobroma cacao) fermentation was carried out
using starter consortia of Saccharomyces cerevisiae, Lactobacillus
plantarum, and Acetobacter aceti with 10% inoculum. The fermented
beans were soaked with sterile water (1:3 wt/v) for the
duration of 1, 3, and 5 h. The treated beans were dried to the
moisture content of 7 ± 1%. The samples were then roasted,
ground and subjected to steam distillation. The volatiles were
extracted and identified using GC-MS. The samples soaked for 1
h scored 100% cut score along with 0.85% fermentation index.
The volatile and non-volatiles were associated with beans treated
in water after fermentation. Volatile compounds were classified
as esters, alcohols, acids, aldehydes, ketones, pyrazines,
hydroperoxides, and hydrocarbons. Most of the oxygenated aliphatic
compounds and aromatics were potentially derived via an
acetic acid and shikimic acid pathways, respectively. Untreated
cocoa beans contained 12 sesquiterpene hydrocarbons potentially
derived through the mevalonic acid pathway and contributed
to harsh notes. Also, these metabolites were completely
absent in the treated samples indicating depletion while soaking.
Thus, the treated samples (1 h) had enhanced quality with high
flavor notes with 8.5 rating on sensory evaluation. Thus, these
soaking treatments with fermentation lead to improvement of
flavor profiles which confers improved cocoa quality.