Cell wall-modifying enzyme activities after controlled atmosphere storage of calcium-treated Fuji apples
A. Ortiz, G. Echeverría, J. Graell and I. Lara
ISHS Acta Horticulturae 858:213-216. 2010.
2010
บทคัดย่อ
In this work, 'Fuji Kiku-8' apples were treated with 2% (w/v) CaCl2 and stored at 1°C and 92% RH under either air or two different controlled atmosphere (CA) regimes for 7 months. Different cell wall-modifying enzyme activities were determined 7 d after removal from storage in order to assess relationships, if any, to changes in fruit firmness and cell wall composition induced by CaCl2 treatment and/or storage atmosphere. Applied calcium was effective in preserving firmness of air-stored fruit but no significant differences in this attribute were found for samples kept under CA regardless of calcium treatment. Results showed high correlation between firmness and covalently-bound pectin content. To a lesser extent, non covalently-bound pectin content was also related to firmness. Solubilisation of pectins, which leads to loss of fruit firmness, may require a previous release of neutral sugar residues from the side-chains of wall-bound pectins by the action of a number of glycosidases such as ß-galactosidase (ß-Gal) or ß-xylosidase (ß-Xyl), which in turn was partially inhibited by CA-conditions during cold storage.