# Production of Volatile Compounds Using Wild Yeasts in a Cocoa Leachate-Based Culture Medium

## TL;DR

This study explores how wild yeasts produce aromatic compounds in a cocoa leachate medium, revealing their potential for enhancing cocoa flavor and using byproducts.

## Contribution

The research identifies specific volatile compounds produced by wild yeasts in a cocoa leachate-based medium, linking them to sensory attributes.

## Key findings

- Twenty-six volatile compounds were identified, with ethanol being the most abundant.
- Three yeast clusters were distinguished based on their volatile compound production profiles.
- Cocoa leachate is shown to be an effective medium for producing desirable aromatic compounds with wild yeasts.

## Abstract

Volatile organic compounds (VOCs) play a crucial role
in cocoa
fermentation, shaping its final aromatic profile. The aim of this
research was to identify the volatile compounds produced by wild yeasts
grown in a culture medium derived from cocoa leachate. VOCs were analyzed
by headspace solid-phase microextraction coupled with gas chromatography–mass
spectrometry and odor activity value screening. A total of twenty-six
VOCs produced by yeast strains were identified and classified into
six families: alcohols, esters, aldehydes, acids, ketones, and pyrazines.
Ethanol was the most abundant (355.28 mg/kg), while the total ester
concentration reached 105.84 mg/kg. Principal component analysis revealed
the separation of the yeast into three main clusters. Strain Y33 belonged
to the first cluster, which was the highest producer of ethanol and
esters associated with fruity perceptions. In the second cluster,
Y29a and Y244 were the main producers of alcohols related to floral
perceptions. In the third cluster, ten yeasts were grouped by their
ability to produce esters. Among them, Y195 and Y110MRS stood out
for producing ethyl octanoate and 3-methybutanal, compounds associated
with fruit and chocolate perceptions. Overall, our findings demonstrate
that cocoa leachate, the main carbon source under real fermentation
conditions, can generate a VOC profile linked to desirable sensory
attributes and thus represents an excellent medium for VOC production
with wild yeasts while contributing to the valorization of an agro-industrial
byproduct.