Improving the keeping quality of pomegranate fruit by intermittent warming

Mollar pomegranates (Punica granatum, Punicaceae) were stored at 0 degrees C or 5 degrees C and 95% relative humidity (RH) for 80 days. Intermittent warming (IW) cycles of 1 day at 20 degrees C every 6 days, during which time the fruit had been stored at 0 degrees C or 5 degrees C, followed by a shelf-life period of 7 days at 15 degrees C and 70% RH were applied. IW during storage at 0 degrees C was the best treatment for maintaining the red skin colour as at harvest. However the red colour of the arils (hue angle) was kept better under warming at 5 degrees C. Although significant changes in the individual anthocyanins were observed in all treatments, particularly after the shelf-life period, the total anthocyanin content of the juice at harvest was maintained. While storage at 0 degrees C avoided decay although increased the risk of chilling injuries such us pitting and husk scald, 5 degrees C-storage reduced these injuries but fungal attacks were not inhibited. After the shelf-life period, IW alleviated chilling injuries without any incidence of decay. Warming treatments gave very good results with respect to storage and the keeping quality of pomegranates, particularly when applied during storage at 0 degrees C.