Influence of fermentation level and geographical origin on cocoa bean oligopeptide pattern.
Peptides and amino acids generated during cocoa bean fermentation are the most important precursors for the development of cocoa aroma, however cocoa oligopeptide fraction is under-investigated. In this study, we perform a deep investigation of the presence of oligopeptides in unfermented, under fermented, and well-fermented cocoa beans from all of the main producing countries, with the aim to obtain a better definition of cocoa quality and a deeper comprehension of biochemical changes occurring during fermentation. Oligopeptides were determined by UPLC/ESI-MS and 35 low-molecular weight peptides were identified and subjected to semi-quantitative analysis. Results showed that fermented cocoas can be differentiated from unfermented cocoas by their possession of a higher total amount of oligopeptides and a lower ratio of vicilin to 21kDa cocoa seed albumin peptides. A variability in the peptide pattern was observed also among well-fermented cocoa samples of different geographical origin, suggesting diversified proteolytic activities.
Department of Food Science, University of Parma, Parco Area delle Scienze 17A, 43124 Parma, Italy. Electronic address: augusta.caligiani@unipr.it.
Augusta
A
Caligiani
Department of Food Science, University of Parma, Parco Area delle Scienze 17A, 43124 Parma, Italy.
Angela
A
Marseglia
Department of Food Science, University of Parma, Parco Area delle Scienze 17A, 43124 Parma, Italy.
Barbara
B
Prandi
Department of Food Science, University of Parma, Parco Area delle Scienze 17A, 43124 Parma, Italy.
Gerardo
G
Palla
Department of Food Science, University of Parma, Parco Area delle Scienze 17A, 43124 Parma, Italy.
Stefano
S
Sforza
D000418:Albumins / Q000737:chemistry; D000596:Amino Acids / Q000737:chemistry; D002099:Cacao / Q000737:chemistry*; D005285:Fermentation; D005843:Geography; D008970:Molecular Weight; D009842:Oligopeptides / Q000032:analysis*; D055314:Seed Storage Proteins / Q000737:chemistry
D000418:Albumins; D000596:Amino Acids; D009842:Oligopeptides; D055314:Seed Storage Proteins; C015575:vicilin protein, plant
Cocoa beans; Fermentation level; Geographic origin; Oligopeptides