1-MCP对八月红梨防褐保鲜的效应

Effect of 1-MCP on Inhibition of Browing of Bayuehong Pear

通过测定1-甲基环丙烯(1-MCP)处理的八月红梨果实不同部位酚类物质含量、多酚氧化酶(PPO)活性、过氧化物酶(POD)活性、脂肪氧合酶(LOX)活性和膜透性,果实常温呼吸强度和乙烯释放速率,以及果实品质和品味,研究1-MCP对八月红梨的防褐保鲜效应。结果表明:1.0μl/L 1-MCP处理可使果实保持较高的硬度、可溶性固形物(TSS)和可滴定酸(TA)含量,明显降低果实的呼吸强度和乙烯释放速率;1-MCP处理的果实酚类物质含量、相对电导率和LOX活性均低于对照,但PPO、POD活性均高于对照;1-MCP能完全抑制八月红梨果实黑皮病的发生,显著降低果心褐变率,推迟果实的后熟和衰老,延长贮藏和货架期。结果还表明:酚类物质含量和POD活性均为果皮大于果心、果肉;PPO活性为果皮、果心大于果肉,果心褐变时间较果皮早,褐变程度较果皮重;八月红梨组织褐变是果实衰老造成的,组织褐变与酚类物质含量呈显著正相关,与PPO活性变化无显著相关。

The effectiveness of 1-MCP on inhibition of pear browning was studied through detection of enzymes activities, phenolic activities as well as respiration rate of Bayuehong pear, Pears exposed to 1.0 μl/L 1-MCP remained higher firmness, total soluble solids and titratable acidity, however, the rates of respiration and ethylene release were reduced markedly. Compared with pears in control, phenolic content, relative conductivity and lipoxygenase activity in treated fruits by 1-MCP declined remarkably, while the activities of polyphenol oxidase（PPO） and peroxidase （POD） were raised. 1-MCP treatment was very effective on inhibiting skin blackening and decreasing core browning rate. It also delayed fruit ripening and senescence, leading to longer storage and shelf life. Phenolic content and POD activity different in various parts of fruit, higher in the peel than in the core and flesh, while PPO was more active in the peel and core than in the flesh. Pear core showed earlier and more severe browning than peel did. All the results indicated that the browning of Bayuehong pear was mainly caused by senescence, and was positively correlated with the content of phenols.