Cell-wall polysaccharides of kiwifruit (Actinidia deliciosa): effect of ripening on the structural features of cell-wall materials

✍ Scribed by Robert J. Redgwell; Laurence D. Melton; Donald J. Brasch

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 765 KB
• Volume: 209
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(91)80156-h

✦ Synopsis

AJBTRACT

Cell-wall polysaccharides were solubilised from cell-wall materials (CWMs) isolated from kiwifruit at 2 ripening stages, after treatment for 1 and 7 days with ethylene. The fractions soluble in cyclohexanefruns-1,2-diaminetetra-acetate (CDTA), Na,CO,, guanidinium thiocyanate (GTC), and KOH were purified by ion-exchange and gel-permeation chromatography, and subjected to methylation analysis. The pectic polymers in the 'I-day fractions had increased proportions of 4-linked galactosyl, 2-and 2,4-linked rhamnosyl, and terminal arabinosyl, xylosyl, and galactosyl residues, and decreased proportions of 4-linked galacturonosyl residues. In the major Na,CO,-soluble pectic fraction, there was an increase in the proportion of branched polymers of high molecular weight during ripening. Therefore, a large proportion of the polyuronides may have been solubilised without significant structural modification, indicating that the action of endo-polygalacturonase was not involved. There was a decrease in M, of the xyloglucan fraction during ripening, but no detectable changes in the primary structure or in the 4-0-methylglucuronoxylan and galactoglucomannan fractions.