Explain the changes in cell wall and intercellular structure

As a result of changes in the cell wall and intercellular structure, all fruits and vegetables undergo softening when cooked, no matter by what method. The changes occur in pectic substances, cellulose, starch  and intercellular air. Cellulose, pectin and hemicellulose, as you have learnt earlier, are the major polysaccharide components in the cell wall of all plant foods.

There has been a rapid progress in understanding the physical and chemical properties of polysaccharides in recent years. Studies on the role of cell wall components in food texture have been done, particularly on pectic substances. Alterations in pigments, formation of acids  and release of low molecular weight sulfur compounds have been reported as the major changes during processing of fruits and vegetables. In a study, reactivation of a pectinesterase has been found in cucumber slices.