Changes in cell wall polysaccharide of harvested peach fruit during storage.

Changes in cell wall structure, decrease in tissue firmness and ethylene production in honey peach [Prunus persica (L.) Batsch, cv. 'Yuhuasanhao'] were investigated after various storage at 5 degrees C and at 20 degrees C. The results showed that during storage, the peak of ethylene production lagged significantly behind the rapid softening of peach fruit, which means that it is not ethylene causes the softening of peach fruit. The structural and compositional changes of cell wall of fruits stored at 5 degrees C and at 20 degrees C suggested that low temperature storage inhibited the changes in pectins and cell wall materials (CWM)-residue fraction and delayed the softening of peach fruit. Ruptures of the pectic main chains rich in galacturonic acid occurred. Loss of arabinose and galactose was detected both in pectins and CWM-residue. These results suggested that softening of harvested peach fruit involved the solubilization and degradation of side chains of pectin and CWM-residue fraction, which were probably due to the increased activities of cell wall polysaccharide-related enzymes. However, the loss of neutral sugars in hemicellulosic polysaccharides was not correlated with fruit softening.