Comprehensive analyses of the postharvest physiology and browning mechanism of pomegranate (Punica granatum L.) during cold storage

ABSTRACT: Pomegranate (Punica granatum L.) belongs to the Punicaceae family, and pomegranate fruit is valued for its social, ecological, and economic aesthetic value, and more recently, for its health benefits. The Tunisian pomegranate, which has soft seeds and large arils that can be easily swallowed, is particularly popular. This study explored the environmental factors that affect fruit skin browning as well as the relationships between changes in enzyme activity and fruit skin browning. In this study, soft-seed pomegranate fruit were stored at chilling injury (CI) temperature (0 °C) and non-CI temperature (8 °C) after harvest to investigate the impacts of these temperatures on CI development and browning and the associated underlying mechanisms. The results revealed that at 0 °C, the CI index, degree of browning, and chlorophyll content were greater than those at 8 °C. Furthermore, storage at 0 °C increased cell membrane permeability and increased polyphenol oxidase activity. A temperature of 0 °C can cause low-temperature damage to pomegranate fruit, whereas at 8 °C, the fruit hardly experience cold damage.