Changes in the carrot (Daucus carota L. cv. Nerac) cell wall during storage

The aim of this study was to examine biochemical changes in cell wall carbohydrates and extensin proteins during long-term storage of carrots (Daucus carota L. cv. Nerac). During the storage period of 6 months, cell wall fractions were isolated from the carrot at various times for carbohydrate and protein analysis. Signs of extensin cross-linking and its concomitant insolubilisation in the cell wall were found after 7 and 12 weeks of storage. During the same period the concentration of galactose and arabinose decreased, while other carbohydrate components as well as the degree of methylesterification remained virtually unchanged. After the 12th week of storage no changes in the extensin or carbohydrates were detected. Oxidative cross-linking between extensin molecules in the cell wall has been implicated in cell wall strengthening and may be part of the mechanism behind the storage-induced firmness of carrots. (C) 2003 Elsevier Ltd. All rights reserved