title: Partial purification and characterisation of the peptide precursors of the cocoa-specific aroma components.
abstract: Essential precursors of the cocoa-specific aroma notes are formed during fermentation of the cocoa beans by acid-induced proteolysis. It has been shown that, in addition to free amino acids, hydrophilic peptides derived from the vicilin-class(7S) globular storage protein are required for the generation of the cocoa-specific aroma notes during the roasting process. To identify those peptides responsible for the generation of the cocoa-specific aroma components, we have developed a procedure for the fractionation of the aroma precursor extract from well-fermented cocoa beans by ligand-exchange and subsequent Sephadex-LH20 chromatography. The cocoa-specific aroma precursor fractions were characterised by matrix-assisted laser-desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF) and the determination of their amino acid sequences by electrospray ionisation mass spectrometry (ESI-MS/MS).
authors: Friedrich-Schiller-University Jena, Institute of Microbiology, Department of General Microbiology and Microbial Genetics, Neugasse 24, D-07743 Jena, Germany. Electronic address: juergen.voigt@uni-jena.de.
authors: Jürgen
authors: J
authors: Voigt
authors: Charité - University Medicine Berlin, Institute of Biochemistry, Charité-Platz 1/Virchowweg 6, D-10117 Berlin, Germany.
authors: Katharina
authors: K
authors: Janek
authors: Charité - University Medicine Berlin, Institute of Biochemistry, Charité-Platz 1/Virchowweg 6, D-10117 Berlin, Germany.
authors: Kathrin
authors: K
authors: Textoris-Taube
authors: Charité - University Medicine Berlin, Institute of Biochemistry, Charité-Platz 1/Virchowweg 6, D-10117 Berlin, Germany.
authors: Agathe
authors: A
authors: Niewienda
authors: Friedrich-Schiller-University Jena, Institute of Microbiology, Department of General Microbiology and Microbial Genetics, Neugasse 24, D-07743 Jena, Germany.
authors: Johannes
authors: J
authors: Wöstemeyer
mesh_terms: D000596:Amino Acids / Q000032:analysis; D002099:Cacao / Q000737:chemistry* / Q000378:metabolism; D005285:Fermentation; D006801:Humans; D009812:Odorants / Q000032:analysis*; D010455:Peptides / Q000032:analysis* / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry; D012639:Seeds / Q000737:chemistry; D012903:Smell; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D053719:Tandem Mass Spectrometry
chemical_list: D000596:Amino Acids; D010455:Peptides; D010936:Plant Extracts
keywords: Aroma; Cocoa beans; Fermentation; Globular storage protein; Mass spectrometry; Peptides