Abstract:

Apple texture is one of the most important quality properties that influences consumers’ acceptability of this
fruit. To evaluate the determinant factor for texture difference in apple fruits, the changes in firmness, crispness, cell wall
components and related enzyme activities in fruits of 4 apple cultivars with different textures were monitored during
fruit growth and ripening in this study. The results suggested that fruit crispness slightly increased whil firmness and the
contents of cell wall components in the 4 apple cultivars showed a decreasing tendency during fruit development. During
fruit ripening, the content of water-soluble pectin (WSP) in the crisp fruit cultivars was higher, while cellulose content
was obviously lower. The activities of polygalacronase (PG) and β-galactosidase were higher in the apple cultivars with
higher crispness ‘Honeycrisp’ and ‘Gala’, but the activities of carboxymethycellulase and pectinmethylesterase disclosed no
significant difference among all cultivars. Therefore, it was proposed that apple texture differed greatly due to variations in
WSP, ionic soluble pectin and cellulose contents as well as PG and β-galactosidase activities.

Key words: apple, texture, cell wall components, crispness, firmness