Involvement of pectolytic micro-organisms in coffee fermentation

Avallone Sylvie, Brillouet Jean-Marc, Guyot Bernard, Olguin Eugenia J., Guiraud Joseph-Pierre. 2002. Involvement of pectolytic micro-organisms in coffee fermentation. International Journal of Food Science and Technology, 37 (2) : 191-198.

https://doi.org/10.1046/j.1365-2621.2002.00556.x

Article de revue ; Article de revue à facteur d'impact

Version publiée - Anglais
Accès réservé aux personnels Cirad
Utilisation soumise à autorisation de l'auteur ou du Cirad.
523347.pdf
Télécharger (176kB) | Demander une copie

Résumé : During the fermentation of Coffea arabica L., the most frequently found pectolytic bacteria were Erwinia herbicola and Klebsiella pneumoniae. These micro-organisms produce pectatelyase which is unable to depolymerize esterified pectins of mucilage without previous de-esterification. Furthermore, the optimal activities are observed at pH 8.5 whereas fermentation conditions are acidic (5.3-3.5). The major lactic acid bacteria, Leuconostoc mesenteroides, do not produce pectolytic enzymes. Only a Lactobacillus brevis strain, rarely isolated with a low frequency, shows a polygalacturonase activity compatible with fermentation conditions. Mucilage decomposition seems to be correlated to acidification and not to enzymatic pectolysis. Inoculation with pectolytic micro-organisms allows microbiological control of the fermentation but does not speed up the process. It would be preferable to use lactic acid bacteria so that the pH remained as close as possible to natural fermentation, where acidification is important. This practice would standardize the coffee fermentation microflora and therefore control the end product quality.

Mots-clés Agrovoc : café, fermentation, polygalacturonase, Bacteria, technique analytique, micro-organisme, mucilage, dégradation, glycosidase, qualité, acidification