تعيين زمان ايجاد خسارت سرمازدگي ميوه انار (. Punica granatum L) در طول نگهداري در سردخانه

Determination of Time of Chilling Injury in Occurrence Pomegranate Fruit (Punica granatum L.) During Cold Storage

This research was conducted to determine the time of chilling injury occurrence in pomegranate fruit during storage. Fruits of two pomegranate cultivars - ʹMalas Yazdiʹ and ʹGolgazi Torsh Haravarjanʹ - were harvested in commercial maturity stage and transferred to postharvest laboratory of Horticultural Science Department of Shiraz University. Fruits were stored at 1°C and 85± 3% relative humidity for 3 months without any treatment. Samples of fruit (in 4 replications) were removed from storage at 10-day intervals and Electrolyte Leakage (EL) and Weight Loss (WL) measured after every 72 hrs. EL was used as an index of chilling injury, with the assumption that the leakage pertains to changes in plasma membrane. Sections of peel were fixed in FAA (Formalin, Alcohol, Acetic acid) for anatomical study. The results showed that EL and WL increased gradually during storage but after 40 days for ʹGolgazi Torsh Haravarjanʹ and 50 days for ʹMalas Yazdiʹ the rate of EL and WL increased sharply, indicating changes in plasma membrane and therefore an indication of occurrence of chilling injury. Chilling injury was higher in ʹGolgazi Torsh Haravarjanʹ than in ʹMalas Yazdiʹ indicating the sensivity of this cultivar to low temperature. The exact time of anatomical changes was not distinguishable during storage, but, in later stages, changes in vacuole membrane permeability and phenolic compound leakage cause browning of peel cells.