Use of GA_3 to Inhibit Flesh Browning Development of Plum Fruit during Storage at Low Temperature

摘要

Flesh browning development of plum fruit during cold storage is the major factor to result in accelerated quality loss and reduced commercial value of the fruit. Experiments were conducted to test the role of GA_3 in inhibiting the flesh browning development of plum fruit during storage at low temperature. Plum fruit were dipped for 3 min into 0 (control), 50, 100 and 200 mul 1-GA_3 solutions, respectively, and then stored for 90 days at 2 °C and 85-90 % relative humidity. Changes in activities of polyphenol oxidase (PPO), peroxidase (POD) and phenylalanine ammonia-lyase (PAL) and concentrations of phenolics and ascorbic acid (AA), in relation to flesh browning development were measured. Application of GA_3 to plum fruit reduced flesh browning development, inhibited activities of POD and PAL, and delayed the decrease of AA concentration and the increases of total phenolic concentration and PPO activity. Accordingly, the results suggested that the inhibition of flesh browning development of cold-stored plum fruit by GA_3 treatment could be due to both a higher AA level and reduced activities of PPO and POD which catalysed oxidation of phenolics. Use of GA_3 exhibited a potential for storage life extension and quality maintenance of plum fruit at low temperature.