Hydroxyl radical is involved in cell wall disassembly and aril breakdown in mulberry fruit during storage

• OH induced cell wall disassembly in CWM of mulberries in vitro.
• OH increased degradation of cellular wall polysaccharides in harvested mulberries.
• The higher aril breakdown incidence was due to the increased cell wall disassembly in treated fruit.

The effect on hydroxyl radical (OH) on cellular wall disassembly and aril breakdown in mulberry fruit was investigated in vitro and in vivo. The in vitro experiment showed OH induced total sugar and uronic acid released from the cell wall material of mulberries in a dose-dependent manner. Then the harvested mulberries were treated with 5 mM OH to find out its effect in vivo. The results suggested that the application of exogenous OH induced degradation of cellular wall polysaccharides, especially water soluble pectin (WSP) and hemicellulose, which was associated with the higher incidence of aril breakdown in OH-treated mulberries. Meanwhile, the results of gel permeation chromatography analysis further demonstrated that OH enhanced depolymerization and structural modifications of polysaccharides of mulberries during storage as experienced by the downshift in molecular mass of WSP and hemicellulose fractions. These results indicated that as a consequence of the enhanced degradation of cell wall polysaccharides, OH could increase the incidence of aril breakdown in harvested mulberry fruit during storage.