Lower cell wall pectin solubilisation and galactose loss during early fruit development in apple (Malus x domestica) cultivar 'Scifresh' are associated with slower softening rate.

Substantial differences in softening behaviour can exist between fruit even within the same species. Apple cultivars 'Royal Gala' and 'Scifresh' soften at different rates despite having a similar genetic background and producing similar amounts of ethylene during ripening. An examination of cell wall metabolism from the fruitlet to the ripe stages showed that in both cultivars pectin solubilisation increased during cell expansion, declined at the mature stage and then increased again during ripening.

Solid-state 13C NMR study of the mobility of polysaccharides in the cell walls of two apple cultivars of different firmness.

Solid-state (13)C nuclear magnetic resonance (NMR) was used to compare differences in mobility of the cell wall polysaccharides of 'Scifresh' and 'Royal Gala' apples after 20 weeks of storage. The texture of 'Scifresh' apples was markedly firmer than that of 'Royal Gala' at the end of storage. In a novel approach Two Pulse Phase Modulation (TPPM) decoupling was combined with cross polarisation (CP) and single pulse excitation (SPE) experiments.

Cell wall structures leading to cultivar differences in softening rates develop early during apple (Malus x domestica) fruit growth.

Background: There is a paucity of information regarding development of fruit tissue microstructure and changes in the cell walls during fruit growth, and how these developmental processes differ between cultivars with contrasting softening behaviour. In this study we compare two apple cultivars that show different softening rates during fruit development and ripening. We investigate whether these different softening behaviours manifest themselves late during ethylene-induced softening in the ripening phase, or early during fruit expansion and maturation.