Influence of fruit stalk on reactive oxygen species metabolism and quality maintenance of peach fruit under chilling injury condition

Abstract

Chilling injury (CI) is a physiological disorder of peach fruit, occurring at low temperature storage, especially at 5 °C. In this study, the influence of fruit stalk retention on fruit quality and reactive oxygen species (ROS) metabolism of white-fleshed peach (cv. Okubo) was investigated. Fruit with and without stalk was exposed to chilling condition and subsequent shelf-life at 20 °C. Fruit physiological changes and ROS metabolism were monitored. The results showed that stalk retention effectively maintained fruit membrane integrity and reduced juice extraction rate under CI condition. ROS metabolism assay revealed that retention of fruit stalk significantly maintained activities of ascorbate peroxidase (APX), peroxidase (POD), and catalase (CAT), and reduced the peak level of hydrogen peroxide (H2O2) of fruit stored at 5 °C. Multivariable analysis (principal component, partial least squares and path analyses) demonstrated that the improvement of fruit quality indexes such as membrane integrity due to stalk retention was mainly achieved by maintaining APX and POD activities.