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Analyse du potentiel qualitatif des cacaos de Madagascar

Abstract : Cocoa is the third most traded commodity in the world and 23 countries are classified as fine cocoa producers according to the ICCO, including Madagascar. The Malagasy cocoa production is classified as 100 % fine cocoa by the ICCO since 2016. It is one of the most famous in the world, even though it only represents about 0.2 % of the world production. Few studies exist concerning the characterization of Malagasy cocoa and its fermentation. Fermentation is a crucial post-harvest treatment step for obtaining the specific aromatic and sensory quality of cocoa. In this work, the quality criteria could be determined and the changes in organoleptic criteria, volatile composition and microorganisms during fermentation were monitored.Most of the cocoa produced in Madagascar belongs to the Criollo and Trinitario varieties. The monitoring of fermentation showed that the sensory negative descriptors « vegetal, earthy, astringent, bitter » of incompletely fermented cocoa beans (24-48 h) were progressively replaced by positive descriptors “cocoa, chocolate, fruity, acid” as measured in cocoa beans at the end of fermentation (96 h-144 h). Likewise, the contents of volatile compounds such as 3-methylbutyl acetate, ethyl acetate, benzaldehyde, tetramethylpyrazine, acetic acid increase during fermentation. The study of microbial flora has made it possible to identify the origin of the production of certain volatile compounds. The Hanseniaspora opuntiae yeast is of particular interest because it is associated with the production of 2-phenylethanol. The study of the yeast communities at the molecular level confirmed the presence of the yeasts identified and highlighted other strains in particular of the Pichia gender which also are potential producers of volatile compounds such as 2-phenylethyl acetate and ethyl acetate.
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Submitted on : Thursday, August 27, 2020 - 3:04:14 PM
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2020LARE0001AChenYenSu.pdf
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  • HAL Id : tel-02923874, version 1

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Alexandre Chen-Yen-Su. Analyse du potentiel qualitatif des cacaos de Madagascar. Sciences agricoles. Université de la Réunion, 2020. Français. ⟨NNT : 2020LARE0001⟩. ⟨tel-02923874⟩

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