Cocoa-specific flavor components and their peptide precursors

SCALONE, GUSTAVO LUIS LEONARDO; DE KIMPE, NORBERT; TEXTORIS-TAUBE, KATHRIN; WÖSTEMEYER, JOHANNES; DE MEULENAER, BRUNO; VOIGT, JÜRGEN

FOOD RESEARCH INTERNATIONAL

ELSEVIER SCIENCE BV

Año: 2019 vol. 123 p. 503 - 515

0963-9969

Essential precursors of the cocoa-specific roasting-flavor notes were formed during proteolysis of the cocoa vicilin-class(7S)globulin by a mixture of cocoa aspartic protease and carboxypeptidase. These could be partially purified by ligand-exchange chromatography. Many constituents of this peptide fraction were destroyed by post-treatment with pepsin, but the cocoa-specific flavor-precursor peptides were largely resistant against pepsin treatment. However, these peptides were not generated when the cocoa vicilin-class(7S)globulin was digested with a mixture of pepsin and carboxypeptidase. By nano-liquid chromatography mass spectrometry, the peptide composition of these peptide fractions were compared in order to identify the putative precursors of the cocoa-specific flavor components. These peptides were assigned to five regions of the cocoa vicilin-class(7S)globulin. Analyzing the roasting products of the different protein fractions by headspace solid-phase microextraction, followed by gas chromatography mass spectrometry, eight volatile compounds were detected, whose occurrence correlated with the sensory detection of cocoa-specific flavor notes.