Aqueous ozone treatment inhibited degradation of cellwall polysaccharides in fresh-cut apple during cold storage

Abstract

The effects of aqueous ozone (AO) treatment on the firmness, cellwall polysaccharide content, enzymatic activity, and gene expression of cell wall-degrading enzymes were investigated in fresh-cut apple during cold storage. AO treatment (1.4 mg L−1 for 5 min) delayed degradation of cellwall polysaccharides to reduce softening of fresh-cut apple. Water-soluble pectin content increased more slowly, while protopectin content, 4% KOH-soluble fraction, and cellulose content decreased at a lower rate in AO-treated fresh-cut apple compared with the control. However, no significant influence was shown on the 24% KOH-soluble fraction. AO treatment promoted increased pectin methylesterase activity, and distinctly inhibited β-galactosidase and α-arabinofuranosidase activities during storage. Polygalacturonase activity was not affected by AO treatment. Meanwhile, AO maintained the intactness of cell walls through repression of Mdβ-Gal and Mdα-Af transcript levels, thereby preserving the textural quality of fresh-cut apple during cold storage.