Avallone Sylvie, Guyot Bernard, Michaux-Ferrière Nicole, Guiraud Joseph-Pierre, Olguin Palacios E., Brillouet Jean-Marc.
2000. Cell wall polysaccharides of coffee bean mucilage. Histological characterization during fermentation.
In : Dix-huitième colloque scientifique international sur le café = 18th International scientific colloquium on coffee ; 18. Internationales wissenschaftliches Kolloquium über Kaffee ; 18° Coloquio cientifico internacional sobre el café. ASIC
Autre titre : Les polysaccharides des parois cellulaires du mucilage des fèves de café. Caractérisation histologique pendant la fermentation
Résumé : The mucilage of pulped coffee beans before and after fermentation was examined by light microscopy. The mucilage of unfermented beans is constituted by two to three layers of elongated palisade-like cells with thin and folded walls attached at their base to the sclerenchymatous parchment. Ruthenium red staining specifically demonstrated the presence of pectic substances. After 20 hours of fermentation, the mucilage tissue is still present with apparently intact cell walls, but it is separated from the parchment. The walls are still stained by ruthenium red suggesting that pectic substances are still present. Therefore it is assumed that no pectinolysis occurs during fermentation or if so it must be to a very restricted and non detectable extent. In conjunction with our biochemical data, it is hypothesized that consumption of sugars by bacterial microflora induces an osmotic pressure gradient from outside to inside the mucilage layer, thus provoking a fracture of mucilage cell walls at their basal site of attachment to the sclerenchymatous parchment.
Mots-clés Agrovoc : Coffea arabica, fève de café, mucilage, pectine, polyholoside, paroi cellulaire, analyse histocytologique, fermentation
Mots-clés géographiques Agrovoc : Mexique
Mots-clés complémentaires : Parche
Classification Agris : Q04 - Composition des produits alimentaires
F60 - Physiologie et biochimie végétale
Auteurs et affiliations
- Avallone Sylvie, CIRAD-CP-CAFE (FRA)
- Guyot Bernard, CIRAD-CP-CAFE (FRA)
- Michaux-Ferrière Nicole, CIRAD-AMIS-BIOTROP (FRA)
- Guiraud Joseph-Pierre, UM2 (FRA)
- Olguin Palacios E., INECOL (MEX)
- Brillouet Jean-Marc, CIRAD-FLHOR-ARF (FRA)
Autres liens de la publication
Source : Cirad - Agritrop (https://agritrop.cirad.fr/263871/)
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