ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Textural and physiological changes during pepino (Solanum muricatum Ait.) ripening.

Heyes, J. A.; Blaikie, F. H.; Downs, C. G.; Sealey, D. F.;

Scientia Horticulturae Year: 1994 Vol: 58 Issue: 1-2 Pages: 1-15 Ref: 32 ref.

1994

บทคัดย่อ

ABSTRACT :

Pepino cv. El Camiuno fruits softened throughout ripening while attached to the bush. An Instron Universal Testing Machine was used to define a range of compressive and tensile textural parameters. A novel tensile test for fruit tissues is described. The pattern of textural change implied that softening was primarily a result of a progressive decline in cell wall strength and loss of cell-to-cell adhesion. In vitro treatments to lower tissue turgor, apoplastic pH, or free calcium were equally effective in softening tissue rings. Pectinmethylesterase [pectinesterase] and polygalacturonase (PG) activities increased during ripening, PG activity appeared just before the first externally visible sign of ripening (purple striping on the fruit surface), and increased during the later stages of fruit softening. Pepino fruits are non-climacteric, since propylene accelerated colour change and fruit softening, but fruits produced little ethylene at harvest and did not produce ethylene autocatalytically in

response to exogenous propylene. Fruit respiration increased transiently in response to propylene, but in control fruits the respiration rate increased only slowly during postharvest ripening. During prolonged storage at 20 deg C the only fruits to produce ethylene at rates over 0.2 micro l kg-1 h-1 were those which subsequently developed stem-end rots.