Effect of non chemical treatments and SO₂ sources on keeping quality of the delayed harvest thompson seedless grapes during cold storage [electronic resource].

Includes reference.

This experiment was conducted during the 2002 and 2003 seasons on seven-year old Thompson seedless grapevines, headtrained and cane pruned, located in a vineyard at El-Santa, Gharbia governorate. The clusters were harvested, in the first week of October at late maturity stage, where soluble solid content was 19.9 and 19.0 % in the two seasons, respectively. The trimmed clusters were treated by one of the following treatments: exposure to IDtraviolet irradiation (UV-C) (254 mn) for 2 min at 22°C, exposure to hot air 38 °c and 85 % RH for 2 h and brief immersion in 35 % ethanol for 30 s at 22°C. The treated clusters were stored at 0 °c and 90- 95% RH for 4 and 8 weeks plus 3 days at 22°C and 80-85 %RH. The clusters quality parameters were decreased by advancing the storage period. Clusters brief immersion in 35 % ethanol for 30 s at 22°C maintained all of the cluster general appearance, overall quality index, cluster parameters and reduced berry shattering. Sodium metabisulfite, as SO₂ generating source, is better than sodium thiosulphate pentahydrate, where it maintained all of the clusters quality parameters.

Summary in Arabic.

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