Effect of Salicylic acid and Polyethylene Glycol Application on Physiological and Chemical Changes of Valencia’ Oranges During Cold Storage
The effect of salicylic acid at 0.5, 1.0 and 1.5 mM and polyethylene glycol at 0.2, 0.4 and 0.6 % on physiological and chemical changes of Valencia Oranges during cold storage were evaluated during 2014 and 2015 seasons. Fruit treated with high concentrations of both substances exhibited trace to light chilling injury which recorded 1.75 and 2.25 scale, respectively. For that, it could be considered that polyethylene glycol at 0.2 & 0.4 % and salicylic acid at 0.5mM treatments are a good pre – storage treatments to minimize chilling injury, reduction in the weight loss %, attaining the highest SSC content and the highest values of L- Ascorbic of oranges storied at low temperature (5°C ± 1).Whereas the high concentrations of both PEG and SA exhibited the highest values of weight loss, the lowest SSC values, low titratable acidity content and L- Ascorbic. Additionally, total phenol and total flavonoid components increased with high SA and PEG concentrations which could be considered the main reason for minimizing chilling injury on Valencia fruits during cold storage. No signs of decay on control or the other used treatments during the two months of cold storage.