Cell wall disassembly during the melting phase of softening in Snow Queen nectarines
Abel Ortiz, Graham B. Seymour, Gregory A. Tucker and Isabel Lara
Postharvest Biology and Technology, Volume 58, Issue 2, November 2010, Pages 88-92
2010
บทคัดย่อ
Nectarine samples of the melting flesh ‘Snow Queen’ cultivar were harvested periodically around the commercial harvest date. A sharp decline in the ratio of insoluble to soluble cell wall materials preceded the melting-like decrease in fruit firmness, apparently arising from depolymerisation of polysaccharides bound tightly to the cell wall. Results suggest that part of the arabinose-rich side-chains removed from the pectic polymers remained linked transiently to the chelator-soluble fraction of the cell wall. Sugar analyses also suggest that cell wall disassembly was aided by previous elimination of galactan side-chains, which may have facilitated pectin solubilisation. Activity patterns of the cell wall-modifying enzymes considered were very similar, the highest levels being found immediately prior to commercial harvest, followed by some increase again in over-ripe fruit. No apparent relationship with the melting phase of fruit softening was observed, which suggests the presence of different isoforms contributing to the total activity levels measured.