| In this study, the internal browning incidence and quality changes in pear fruit(Rosaceae Pyrus, Duchesne.Cui Guan) treated with 1-methylcylcopropene (1-MCP) andhypobaric storage were investigated. The results were as follows:1.'Cui Guan' pears were exposed to 0, 0.25, 0.5, 1.0 or 2.0μL/L 1-MCP at 20℃for20h, then stored at 2℃for up to 40 days before ripening at 20℃. In addition, another lotof fruit were stored at 2℃for 40 days and then treated with 1-MCP concentrations of 0,0.5 and 1.0μL/L at removal and held for ripening at 20℃. Ethylene production andrespiration rate were efficiently inhibited by 1-MCP in fruit treated before storage andtreated at concentration of 1.0μL/L after storage but not in fruit treated after storge at0.5μL/L. Fruit quality was not affected by 1-MCP treated after storage at 0.5μL/L either.Parameters associated with ripening processes were significantly inhibited by 1-MCP at0.25～1.0μL/L treated before storage and 1.0μL/L treated after storage, including softening,MDA content, relative conductivity, loss of Vc content and internal browning, whiletreatment before cold storage at 2.0μL/L enhanced internal browning and induced thedecrease of fruit quality. It is suggested that 1-MCP might be a potent compound forextending both storage period and shelf life of 'Cui Guan' pear.2. Compared with the air-treated fruit, treatment with 1.0μL/L1-MCP maintainedsignificantly higher levels Vc content and total phenolics and maintained the balance ofactiveated oxgen metabolism, inhibited the increase in superoxide radical production, MDAcontent and PPO activity, and the decrease in fruit firmness. Fruit treated with 1-MCP alsoinhibited the occurence of internal browning. Data obtained suggest that 1-MCP maymaintain the balance of active oxygen metabolism in pears, thereby delaying fruitsenescence and inhibiting internal browning.3. The effects of hypobaric treatment at 70kPa and 40 kPa for 40d stored at 2℃onphysiological and quality parameters in pear fruit during storage period and shelf life wereinvestigated. The results indicated that treatment with 70kPa hypobaric storage inhibitedethylene production and respiration rate. It maintained lower level of membancepermeability, MDA content, internal browning and retarded firmness and Vc contentdecrease. But treatment at 40 kPa promoted internal browning incidence and decline fruitquality and it has a negative effect on the fruit flavor.4. 1-MCP treantment combined with hypobaric cold storage significantly inhibitedethylene production and respiration rate and delayed the peak ethylene and respiration,maintained the quality of the fruit. Compare with fruit treated with hypobaric storage and1-MCP alone, hypobaric+1-MCP treantment has more significant effect on the maintenanceof fruit quaulity. |
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