Two molecules newly identified by Mass Spectrometry in fermented cocoa beans have a strong impact on chocolate sensory quality.

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Trevor Hutchinson
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Sommerer a a Plateforme Polyphénols, UMR SP, INRA, Montpellier Supagro, Université de Montpellier, 34060 Montpellier, Fr

1 Two molecules newly identified by Mass Spectrometry in fermented cocoa beans have a strong impact on chocolate sensory quality. Noémie Fayeulle a, Anna Vallverdú-Queralt a, Jean-Claude Boulet a, Jean-Michel Roger b, Clotilde Hue c, Renaud Boulanger d, Véronique Cheynier a, Nicolas Sommerer a a Plateforme Polyphénols, UMR SP, INRA, Montpellier Supagro, Université de Montpellier, Montpellier, France b UMR ITAP, IRSTEA, 361 rue J.F. Breton, BP 5095, Montpellier, France c Valrhona SA, 8 Quai du Général de Gaulle, Tain l Hermitage, France d UMR Qualisud, CIRAD, TA 80/16, 75 Avenue JF Breton, Montpellier Cedex 5, France 1

2 Polyphenols & Fermentation process Polyphenols in plants Secondary metabolites produced by plants Wide family of molecules Defence, protection, colour Polyphenols in cocoa Mostly flavan-3-ols Highly reactive molecules Bitterness and astringency in raw cocoa beans Epicatechin Procyanidin dimer Wide range of potentially new molecules ph and T C variations + metabolites Raw Beans Fermentation Fermented Cocoa Beans Drying 2

Impact on chocolate taste 12 fermented cocoas

groups Applied to the corresponding cocoas Focus on

beans Mass spectrometry widely used for polyphenols

and quantification after extraction Liquid

mass spectrometry (mass signal (m/z) and relative

3 Impact on chocolate taste 12 fermented cocoas Standardized process 12 chocolates sensory groups Applied to the corresponding cocoas Focus on polyphenol content : Polyphenols extraction from the beans Mass spectrometry widely used for polyphenols detection Fast and accurate Detection, identification and quantification after extraction Liquid chromatography (molecules separation) Low resolution mass spectrometry (mass signal (m/z) and relative quantity) Use of the polyphenols relative quantity in fermented cocoas beans to evaluate the sensory poles 3

4 Problematic link between cocoa molecules and chocolate taste Statistical treatment of the polyphenols relative quantity : Pole 1 Pole 4 List of 32 mass signals (=type of molecules) Pole 3 Which molecules allow the grouping of the sensory poles? Mainly flavan-3-ols Among them two signals with significant impact Pole 2 m/z = 605 m/z = 893 Reported in cocoa not identified PLS-DA Purpose of this work : identify these two mass signals 4

5 Hypothesis: ethyl bridged flavanols Ethyl Bridged flavanols? Ethyl Bridge Molecular Weight : g.mol Ionized Molecular Weight : g.mol CH 3 Epicatechin Epicatechin Molecular Weight : Acetaldehyde + H g.mol Acetaldehyde + H + Low ph Ionized Molecular Weight : g.mol Epicatechin 5 Procyanidin dimer Low ph

6 How to confirm this hypothesis? Structural information Determine the number of molecules in the samples Compare with a reference Polyphenol extract from cocoa beans Chromatographic separation High resolution mass spectrometry Polyphenol extract from cocoa beans Chromatographic separation Low resolution mass spectrometry Model solution epicatechine + dimers + acetaldehyde at low ph VS 6

7 High resolution mass signals Exact chemical formula Structural information Exact mass signal & chemical formula Theoretical Ionized mass Experimental Ionized mass Mass defect (mda) 1,8 1 Theoretical chemical formula C 32 H C 47 H Experimental chemical formula C 32 H C 47 H

8 Structural information : fragmentation scheme H 2 C CH 2 The fragmentation pattern is specific from ethyl bridged flavanols The structure is confirmed for both signals at m/z = 605 and m/z = 893 8

9 Low resolution mass spectrometry numbers of different molecules in samples Intensity (UA) Intens. x Intens. 0.0 x F-SC204-3_10066.d: EIC All MS Intens. x10 m/z = m/z = 893 Cocoa extract 1121-NFA179-solmodepiB2-T48h_10067.d: EIC All MS Model solution Intensity (UA) Intens. x F-SC204-3_10066.d: EIC All MS Cocoa extract 1121-NFA179-solmodepiB2-T48h_10067.d: EIC All MS Model solution Time [min] 4 isomers Time (min) Time [min] 5 isomers Time (min) UHPLC-ESI-IT-MS, negative mode 9

10 Conclusion After statistical analysis, two unknown mass signals have been highlighted These molecules discriminate the chocolate sensory poles Mass spectrometry allowed to identify these two mass signals as ethyl bridged flavanols 10

11 Thanks for your attention Special thanks to Anna Vallverdú-Queralt Emmanuelle Meudec Jean-Claude Boulet Jean-Michel Roger Clotilde Hue Renaud Boulanger Véronique Cheynier Nicolas Sommerer 11

Introduction. Joanna Oracz 1 Ewa Nebesny 1 Dorota Żyżelewicz 1

Introduction. Joanna Oracz 1 Ewa Nebesny 1 Dorota Żyżelewicz 1 DOI 10.1007/s00217-015-2494-y ORIGINAL PAPER Changes in the flavan 3 ols, anthocyanins, and flavanols composition of cocoa beans of different Theobroma cacao L. groups affected by roasting conditions Joanna