Hypobaric storage reduced core browning of Yali pear fruits

Core browning is a major issue of pear fruits. The primary factor leading to development of core browning is high levels of CO2 in storage. Hypobaric storage is a new postharvest technique to extend the shelf life of fruits and can reduce CO2 partial pressure. In this study, the effect of hypobaric storage on core browning of Yali pear fruits (Pyrus bretschneideri Rehd.) was evaluated. Results showed that fruits after 0.025 MPa hypobaric treatment had 37.3% lower rate of core browning development and higher acidity and soluble solid content than control fruits. In addition, 0.025 MPa hypobaric treatment increased activities of cytochrome oxidase (CCO) and peroxidase (POD), and 2,2-diphenylpicrylhydrazyl (DPPH) radicals and superoxide anion scavenging capabilities. In comparison with the control, hypobaric treated fruits had lower activity of polyphenol oxidase (PPO) and higher level of total polyphenols. Hypobaric treatment also reduced an increase of succinate dehydrogenase (SDH) and glucose-6-phosphate dehydrogenase (G-6-PDH) activities. Results indicated that hypobaric treatment could control core browning of pear fruits by regulating reactive oxygen species (ROS) generation and elimination enzymes to maintain cell membrane integrity and reduce enzymatic browning.