Effect Of Harvest Date And Ozone Treatment On Storage Quality And Physiological Changes Of 'Fuji' Apple

In this paper,'Fuji'apples in Luochuan were picked at 168d,171d,174d,177d,180d and 183d after full bloom and stored in low temperature, the storage qualities and physiological changes with different harvest date were studied, and the apples picked at 177d after full bloom were treated with ozone at intervals, the preserve function of ozone and its effect on postharvest physiology and storage quality were studied, which provides technical support for the judging of proper harvest date and the application of ozone in cold storage.The result showed :(1) During cold storage, the change trends of respiration rate and ethylene production rate in fruits harvested at different time were similar, and harvest date influenced the value of climacteric peak but not the advent time; the peak value of fruits picked at 168d and 183d after full bloom were higher than others.(2) The water loss was high in fruits picked at 168d after full bloom; the firmness decreased quick and rotted ratio was high in fruits picked at 180d and 183d after full bloom; the contents of soluble solid ,organic acid and Vc changed slow ,and it also had a low water loss and rotted ratio in fruits picked at 171d—177d after full bloom .The'Fuji'apple in Luochuan for long storage should be harvest at 171d—177d after full bloom, and the firmness≥8.4kg/cm2 and SSC≥13.8% at harvest.After storage , the firmness≥6.4kg/cm2 and SSC≥12.4%.(3) 6mg/m3 Ozone treatment inhibited respiration rate, ethylene production rate, MDA level, membrane permeatility and poly-phenol oxidase(PPO) activity, retained higher activity of POD.(4) Ozone retained decreasing of fruit firmness, delayed the loss of soluble solid contents and water , accelerated the loss of Vc, but no significant differences were found in contents of organic acid.