Investigating time dependent cocoa bean fermentation by ESI-FT-ICR mass spectrometry

• Published in: Food research international Vol. 133; p. 109209
• Main Authors: Kuhnert, Nikolai, D'souza, Roy N., Behrends, Britta, Ullrich, Matthias S., Witt, Matthias
• Format: Journal Article
• Language: English
• Published: Canada Elsevier Ltd 01.07.2020
• Subjects: Amino Acids; Cacao; Cocoa; Data bases; Fermentation; Mass spectrometry; Metabolomics; Peptides; Spectrometry, Mass, Electrospray Ionization; Metabolomics; Fermentation; Cocoa; Mass spectrometry; Data bases
• ISSN: 0963-9969; 1873-7145
• DOI: 10.1016/j.foodres.2020.109209

[Display omitted] •Cocoa bean fermentation was followed by ultra high resolution mass spectrometry.•Changes of excess of 8000 cocoa constituents in van Krevelen diagrams were followed during fermentation.•Major changes occur in CHON compounds assigned to short peptides and derivatives.•Theoretical product databases allow suggestions of tentative reaction products of short fermentation peptides. A cocoa bean fermentation series, comprising bean samples taken every 24 h of a seven-day cocoa fermentation was analyzed by ultra-high-resolution mass spectrometry using the ESI-FT-ICR technique. Data were acquired in both positive and negative ion mode. At early fermentation times around 2000 signals could be resolved raising to a maximum of 8000 signals in each ion mode towards the end of the fermentation. Molecular formulae were assigned to a large number of observed peaks leading to ion statistics classifying cocoa constituents according elemental composition. Time dependent van Krevelen diagrams were constructed allowing the tracking of chemical changes in bean composition. In particular, the number of CHON compounds assigned to short peptides and their derivatives were shown to undergo significant chemical transformations. Theoretical MS data bases were constructed containing all possible peptides up to a length of ten amino acids and putative derivatives expected to be formed during microbial fermentation. Experimental m/z values were compared to these databases and conclusions drawn with respect to the composition of fermenting beans with tentative fermentation products suggested.