Structural ripening-related changes of the arabinan-rich pectic polysaccharides from olive pulp cell walls

• Tipo: Artigo em Revista Científica Internacional
• Data: 2007

Autores

Cardoso, SM (Autor) Outra; Ferreira, JA (Autor) Outra; Isabel Mafra (Autor) REIT; Silva, AMS (Autor) Outra; Coimbra, MA (Autor) Outra

Revista

Título: Journal of Agricultural and Food Chemistry

Vol. 55

Páginas: 7124-7130

ISSN: 0021-8561

Editora: American Chemical Society

Indexação

ISI Web of Knowledge - 39 Citações

Scopus - 49 Citações

Outras Informações

ID Authenticus: P-004-85C

DOI: 10.1021/jf070769w

Abstract (EN): In this study, the structural features and ripening-related changes that occur in the arabinan-rich pectic polysaccharides highly enmeshed in the cellulosic matrix of the olive pulp fruit were evaluated. These pectic polysaccharides, obtained from two consecutive harvests at green, cherry, and black ripening stages, account for 11-19% of the total pectic polysaccharides found in the olive pulp cell walls and were previously shown to occur as calcium chelating dimers. On the basis of the C-13 NMR, (H-1, C-13) gHSQC, 2D COSYPR, and (H-1,C-13) gHMBC carbon and proton resonances of the variously linked arabinosyl residues, we propose a tentative structure. This structure is particularly characterized by T-beta-Araf (1 -> 5)-linked to (1 -> 3,5)-Araf residues and by the occurrence of branched and linear blocks in the arabinan backbone. Methylation analysis showed that these pectic polysaccharides of black olives have more arabinan side chains, which were shorter (less (1 -> 5)-Araf), highly branched (more (1 -> 3,5)-Araf), and with shorter side chains (fewer (1 -> 3)-Araf) than those of green and cherry olives. Quantitative C-13 NMR data indicated that these modifications involved the disappearance of the characteristic terminally linked beta-Araf residue of the arabinans. This odd feature can be used as a diagnostic tool in the evaluation of the stage of ripening of this fruit, as well as a marker for the presence of olive pulp in matrices containing pectic polysaccharides samples.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 7