MoLife Research Seminar by:
Ms. Neha Kumari, PhD Student cacao projekt COMETA - Workgroup M. Ullrich, Jacobs University Bremen, Bremen, Germany
Title of the talk:
Towards the understanding of Cacao Proteome
Before getting transformed into chocolate and other cocoa products, the content of cocoa beans undergoes a series of complex metabolic changes during processing steps involving fermentation, drying and roasting. Cocoa storage proteins undergo the most intense modifications during fermentation, where microbiological fermentation products-triggered enzymatic reactions lead to their extensive breakdown yielding peptides and amino acids, which are important flavor precursors.
Our research study focused on the comprehensive and comparative protein analysis of the cocoa beans from diverse origins and different hybrids. Protein profile of the cocoa beans starting from the fresh non-fermented beans to the different stages of fermentation and finally towards the fully fermented/dried beans was studied via SDS-PAGE and Two-dimensional polyacrylamide gel electrophoresis. All major protein spots obtained were subjected to proteolytic digestion and MALDI-TOF MS analysis in order to assign them to respective cocoa proteins. Post-translational modification of the cacao proteins was successfully established. The diversity of oligopeptides generated by the proteolytic degradation at different stages of fermentation was identified spectrometrically via UHPLC-ESI-MS/MS analysis. The detected diversity and dynamics of protein and peptide profile will help to define the biochemical markers of distinct steps of the fermentation process, which in turn will help in mapping the precursor based variability and linking it to the taste and aroma of the final product.
Further information by:
Prof. Dr. Matthias Ullrich, Professor of Microbiology (Focus Area: Health - Life Sciences & Chemistry) Email: m.ullrich [at] jacobs-university.de - Link to Homepage: https://ses.jacobs-university.de/ses/mullrich