Coating treatments in postharvest behaviour of oranges.
Martinez Javega, J. M.; Cuquerella, J.; Rio, M. A. del; Mateos, M.;
Technical innovations in freezing and refrigeration of fruits and vegetables. Year: 1991? Pages: 79-83 Ref: 9 ref.
1991
บทคัดย่อ
In a first experiment, Valencia oranges were dipped in imazalil solution (800 p.p.m.), sized and sorted, and either coated with various wax formulations or seal packaged with heat-shrinkable polyolefin (Cryovac) film. After 15 days' storage at 20 deg C/70% RH, weight loss was lower in coated fruits (3.1-4.5%) than in uncoated control fruits (6.3%), and was negligible in seal-packaged fruits (0.5%). Waxing and seal-packaging had no effect on the TSS:acidity ratio. Waxing and seal-packaging increased internal fruit CO2 concentration and juice ethanol content, but no off-flavours developed in any treatment. Waxing with a 15% resin formulation resulted in the highest internal CO2 concentration and ethanol content (6.7% and 68.2 mg/100 ml, respectively). After 120 days' storage at 3 deg /85% RH, followed by ripening for 7 days at 20 deg /70% RH, weight loss was lower in coated fruits (8.6-12.3%) than in uncoated control fruits (15.6%), and was lowest in seal-packaged fruits (1.1%). In coated fruits, waxing with a 10% carnauba formulation resulted in the highest weight loss. Seal packaging controlled stem-end rind breakdown, which developed in 50.4% of uncoated fruits and 8.1-15.3% of waxed fruits, and rind pitting which developed in 4.9% of uncoated fruits and 0.9-9.7% of waxed fruits. Waxing and seal packaging increased internal CO2 concentration and juice ethanol content; off-flavours were detected in fruits waxed with a 10% resin formulation. In a second experiment, Valencia oranges were injured by piercing the flavedo of the fruit and then immersed in a Penicillium digitatum spore suspension. Fruits were held at 20 deg /90% RH for 24 h and then held at 35 deg for 70 h, followed by storage at 20 deg /90% RH for up to 30 days or at 3 deg /85% RH for up to 100 days. Curing reduced decay development at 20 deg but did not reduce decay in long-term storage at 3 deg . No symptoms of decay were evident in cured fruits stored for 6 days at 20 deg .