Vol. 82 No: 2

Title:
Analysis of cell wall polysaccharides during storage of a local melon accession 'Wasada-uri' compared to the melon cultivar 'Prince'

Authors:
T. NISHIZAWA and A. ITO

pp: 227-234

Abstract:
Changes in cell wall polysaccharides associated with fruit softening under storage conditions at 20°C were compared between ´Wasada-uri` (a “five-carpel-type” melon accession) and ´Prince` (a “three-carpel-type” melon cultivar). Ethylene production in ´Prince` showed a peak on day-2 and decreased rapidly thereafter, while that of ´Wasada-uri` remained low until day-10. Carbon dioxide production in both varieties was highest at fruit harvest, and decreased rapidly during storage. Although flesh firmness in both varieties decreased continuously during storage, a distinct difference was observed, resulting in the firmness of ´Prince` flesh decreasing to between 16 - 44% that of ´Wasadauri`. In the “water-soluble” pectin fraction, uronic acid concentrations in ´Prince` increased linearly until day-5, while those of ´Wasada-uri` remained low. In the “Na₂CO₃-soluble” fraction, uronic acid concentrations in ´Wasada-uri` increased from day-3 to day-5, while those of ´Prince` decreased from day-2 to day-10. Neutral sugar concentrations in the “Na₂CO₃-soluble” fraction decreased during storage, but there was no apparent difference between ´Wasada-uri` and ´Prince` melons. In the “Na₂CO₃-soluble” fraction, ´Wasada-uri` showed higher galactose, but lower arabinose concentrations compared to those of ´Prince`. Cellulose concentrations in ´Wasada-uri` were 15 - 43% higher than those of ´Prince`, but the values changed slightly during storage. These results suggest that the long shelf-life of ´Wasada-uri` melon is due to the maintenance of cell wall integrity in the covalently-bound pectin polymers, and/or in the abundance of cellulosic polysaccharides.

Full text: JHSB Subscribers     ISHS members & other users
(PDF 89320 bytes)

Go back to previous page