In search of perfect cocoa flavour

The “Cocoa-Chain” project “Quality improved Cocoa and Cocoa-based Products with Flavour Profiles on Demand – From Farm to Chocolate Bar” is researching flavour in Germany and Peru. Geisenheim University’s Dr. Christian von Wallbrunn, a scientist at the Institute for Microbiology and Biochemistry, is investigating the microbiological characterisation of cocoa fermentation and the development of a fermentation starter for testing.

By Dr. Jörg Häseler

The project has great potential given the numerous research possibilities that remain with cocoa fermentation. For instance, what happens when enzymes are added to those already inherent to the cocoa bean? Or how can the flavours that change during drying be influenced? Cocoa that has not been dried or only dried briefly has very green, astringent notes. In some cases there are even flowery notes, which then become more chocolaty the more the cocoa is dried. Here as well there are interesting issues and approaches, thanks to the extreme diversity in cocoa’s world of flavours.
The preliminary stages of the flavour which later form the typical cocoa taste can emerge in a variety of situations, one of which is during the fermentation of the cocoa seeds. At present, this is an uncontrolled process, meaning that the quality cannot be reliably reproduced, and fermentation processes that are conducted incorrectly can induce fungus contamination which can cause problems with mycotoxins.
This project is particularly focused on the characterisation of the biodiversity of the yeasts in cocoa fermentation. One facet examines which wild or natural yeasts are already inherent to the cocoa. Another is researching the effects on the flavour when further yeast strains are added in order to control the fermentation process and retain desired flavours.
A characterisation of spontaneous cocoa fermentations is planned during the project’s first year. Year two will then compare the results of adding various fermentation starters in order to produce findings on the differences in the fermentations and the flavourings. The project partners in Germany are the University of Hamburg, the Hamburg University of Applied Sciences and the Julius Kühn Institute in Berlin. The Peruvian participants are the two universities in Lima, Universidad Peruana Cayetano Heredia and Universidad Nacional Agraria La Molina, as well as other
Peruvian partners and cocoa cooperatives.