Hot water treatment and duration alleviates chilling injury of mango (Mangifera indica L.)

Low temperature storage is the most effective method of extending postharvest life and marketing period and maintain fruit quality. Unfortunately, for chilling injury (CI) sensitive fruits, low temperature storage may be detrimental due to CI which reduces fruit quality and customer acceptance, limits marketing and compromises storage for long periods. The effects of storage temperature and hot water at various temperatures and durations on alleviation of mango chilling injury were evaluated on 'Keitt' mango fruit cultivar in Botswana. Mango fruit at physiological maturity were dipped in water at room temperature (25 +/- 2 degrees C-control), or in a hot water bath (50 and 55 degrees C for 3, 5 or 10 min) and subsequently stored at 4, 7, 10, 13 or 25 +/- 2 degrees C (95% relative humidity). Storage temperature, hot water treatment temperature and duration significantly (P<0.05) influenced the mango CI incidence and severity. As storage temperature decreased below 13 degrees C, CI injury increased. As water temperature and treatment duration increased CI incidence and severity significantly (P<0.05) decreased. There was a significant (P<0.05) effect of the storage temperature and water temperature interaction on mango proline content and electrolyte leakage immediately after cold storage and after a 7-day shelf life period. As the storage temperature and water temperature decreased, the proline content and electrolyte leakage increased significantly (P<0.05). Greatest reduction in CI were obtained by applying hot treatment at 55 degrees C for 10 min and with storage temperatures of 7 degrees C.