Chilling injury as an indicator of critical temperature for cold storage of guava (Psidium guajava L.) cv. Allahabad Safeda

The critical temperature for cold storage of guava cutivar Allahabad Safeda and the changes in physico-chemical attributes during its storage were studied. Fruits were stored at 5, 8 and 15° C with 85–90% relative humidity and withdrawn weekly from cold storage and kept at ambient condition (18–20° C and 65–70% RH) for analysis. Chilling Injury (CI) symptoms, characterised by browning of peel, development of pitting on fruit surface and desiccation of fruit, appeared after 2 weeks in the fruits stored at 5° C. These symptoms became more aggravated when the storage at ambient condition prolonged upto 6 days and when the fruits did not ripen uniformly. The CI symptoms in the fruits stored at 5° C showed membrane damage, i.e. higher electrolyte leakage values and low ethylene levels. However, the fruits stored at 8 and 15° C did not exhibit any symptoms of CI and ripened well until 3 weeks of cold storage.