Intermittent Warming Affects Cell Wall Composition of 'Fantasia' Nectarines during Ripening and Storage
| Autor: | Christopher B. Watkins, Debra M. Dawson, Laurence D. Melton |
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| Rok vydání: | 1995 |
| Předmět: | |
| Zdroj: | Journal of the American Society for Horticultural Science. 120:1057-1062 |
| ISSN: | 2327-9788 0003-1062 |
| DOI: | 10.21273/jashs.120.6.1057 |
| Popis: | Cell wall changes in 'Fantasia' nectarines (Prunus persica (L) Batsch var. nectarina (Ait) maxim) were determined after storage at 0C with or without intermittent warming (at 20C at 2-week intervals) and after ripening. For comparison, fruit were examined at harvest and after ripening without storage. Fruit stored continuously at 0C for 6 weeks became mealy during ripening, whereas fruit subjected to intermittent warming ripened normally. Ripening immediately after harvest was associated with solubilization and subsequent depolymerization of pectic polymers and a net loss of galactosyl residues from the cell wall. No solubilizatio n of pectic polymers from the cell wall occurred during storage of fruit at 0C. Mealy fruit, ripened after continuous storage at 0C, showed only limited solubilization of pectins and depolymerization, high relative molecular weight (Mr) polymers being predominant. During ripening after storage, pectic polymer solubilization was not as extensive in intermittentl y warmed fruit as in fruit undergoing normal ripening but solubilized polymers were depolymerized, low Mr uronic acid-rich polymers becoming predominant. Intermittent warming of fruit resulted in significant softening during storage, alleviating the development of mealiness by promotion of cell wall changes associated with normal ripening. Normal ripening of nectarines and peaches is characterized by loss of flesh firmness, a decrease in insoluble pectin, and an increase in soluble pectin (Ben-Arie and Lavee, 1971). Concomi- tantly the Mr of soluble pectins decreases (Pressey et al., 1971). Loss of arabinosyl and galactosyl residues from the cell wall during ripening was reported by Gross and Sams (1984). Recently, we have shown that these events are coordinated with solubiliza- tion of high Mr uronic acid-rich polymers from the cell wall and removal of galactan side chains from pectic polymers in the cell wall material (CWM), which occur during the initial 2 days of ripening (Dawson et al., 1992). The latter stages of ripening were characterized by the degradation of solubilized high M r pectins resulting in a decrease in molecular size (Dawson et al., 1992). Physiological measurements, such as cation exchange capacity and calcium uptake indicate that the ability of the nectarine tissue to bind calcium decreases significantly during ripening, suggest- ing that calcium binding sites are lost due to pectic solubilization |
| Databáze: | OpenAIRE |
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