N-223. Analysis of Microbial Communities Present During Post-Harvest Fermentation of Trinidadian Cocoa

A. C. Kurzweil, R. P. Roberts, L. E. Wimmers, J. E. M. Watts;
Towson Univ., Towson, MD.

The seeds of the cocoa tree Theobroma cacao, undergo fermentation, drying, and roasting before they are used in the production of a variety of food products such as cocoa powder and chocolate. The characteristic flavors produced are thought to be highly influenced by the cultivar of cocoa harvested, however, the involvement of the microbial community associated with the fermentation of the pulp surrounding the cocoa seeds is, as yet, unknown. This study focuses upon the succession of microbial communities during the fermentation process of seeds produced by Trinitario cocoa trees in Trinidad. Samples of the fermenting seeds were collected every 8 hours during the seven-day fermentation process. Microbial community DNA was extracted for each time point and subjected to denaturing gradient gel electrophoresis (DGGE) to provide rapid fingerprints of the microbial community and provide insight into temporal changes. Clone libraries of the 16S rRNA gene were also constructed from the fermentation to obtain further detail of the microbial species involved in the Trinidadian fermentation process. Preliminary DGGE analysis indicates that the fermentation involves defined microbial communities that alter temporally indicating a characteristic succession of microbial species.