Sugar Composition of Cucumber Cell Walls During Fruit Development

The sugar composition of pickling cucumber cell walls was analyzed in seven cucumber sizes. Relative to total cell wall sugars, glucose did not change, while the other major neutral sugars, galactose, xylose and mannose, underwent relatively small declines during fruit development. The ratios of galacturonic acid/rhamnose and galacturonic acid/arabinose showed large increases during fruit growth, which indicated that pectin structure may change. Pectin methylation in the mesocarp tissue increased from 35 to 64% as cucumber fruit matured. A positive correlation was observed between the firmness of cucumber mesocarp tissue and the total amount of cell wall sugars in the fresh tissue. Cucumber peel tissue contained 4 to 5‐fold higher sugar concentrations than either the mesocarp or endocarp tissues.