Effects of natamycin coating compounds on fresh-keeping of grape during storage

In order to investigate the physiological mechanisms of natamycin combined with chitosan coating compounds on fresh-keeping of red-globe grape, 1% chitosan combined with 0.20%, 0.40%, 0.60%concentration of natamycin respectively was used to be coated on red-globe grape , which was compared with untreated control and the sample was coated with 1% chitosan in cool storage conditions. The results showed that the decay rate of the grapes in the treatment groups reduced. Coating fusion liquid with different concentration of natamycin and 1% chitosan could increase the activity of the phenylalanine ammonia-lyase (PAL) and the MDA contents, with the polyphenol oxidase (PPO) activities of red-globe grape restrained. Meanwhile, the activities of superoxide dismutase (SOD) and peroxidase (POD) increased. Coating fusion liquid with 0.40% natamycin and 1% chitosan had better effect on the storage of the red-globe grape, and the decay rate is only 8.52% after 120 days in cool storage. Meantime, the compounds maintained the low activities of respiratory intensity, delayed the senescence and softening of fruit, and prolonged the storage time of the red-grape fruit. This paper provides a new method for fresh-keeping of grape.