1-MCP处理对早晚熟枇杷鲜果采后生理效应的影响

Effects of 1-MCP Treatment on Postharvest Physiology of the Early and Late-maturing Varieties of Loquat Fruits

目的研究气调保鲜包装结合1-甲基环丙烯(1-Methylcyclopropene,1-MCP)处理对枇杷采后生理效应的影响。方法以早晚熟"白玉"、"丰玉"枇杷为实验材料,采用1-甲基环丙烯对其进行处理,再使用气调保鲜包装(厚度35μm),将其在冷藏温度为(6±1)℃的条件下贮藏,观察其采后生理变化特性及不同品种之间的贮藏性能差异。结果 1-MCP处理可抑制枇杷果实硬度、可溶性固形物含量和可滴定酸含量的下降,延缓枇杷的褐变、过氧化物酶(Peroxidase,POD)活性的上升,减少枇杷的腐烂率,促进枇杷果实多酚氧化酶活性(Polyphenoloxidase,PPO)、脂氧合酶(Lipoxygenase,LOX)活性的下降。枇杷品种白玉的呼吸速率、POD、PPO活性及褐变指数较丰玉高,LOX活性和丙二醛(Malondialdehyde,MDA)含量增加明显,其硬度和营养成分含量较低;丰玉的腐烂率高于白玉。结论采用气调保鲜包装结合1-MCP处理延缓了枇杷在冷藏过程中营养物质的下降,进而延迟了枇杷褐变和衰老进程。其中早熟品种白玉枇杷的褐变发生率和膜脂过氧化程度更高。

The work aims to study the effects of modified atmosphere fresh-keeping packaging combined with 1-Methylcyclopropene(1-MCP) treatment on postharvest physiology of loquat fruits. The early and late-maturing varieties of "Baiyu" and "Fengyu" loquat fruits were selected as experimental materials, treated with 1-MCP and then stored at(6±1) ℃in modified atmosphere fresh-keeping packaging(thickness: 35 μm). The postharvest physiological characteristics and the difference in storage performances among different varieties were observed. The results showed that, the decrease of fruit hardness, soluble solids and titratable acid content could be inhibited, the browning of loquat and increase of peroxidase(POD) activity could be delayed, the rot rate of loquat could be reduced, and the decline of the activity of polyphenoloxidase(PPO) and Lipoxygenase(LOX) in loquat fruits was promoted with 1-MCP treatment. The respiration rate, POD and PPO activity and browning index of Baiyu loquat were higher, LOX activity and malondialdehyde(MDA) content increased significantly, and its hardness and nutrient content were lower than those of Fengyu. The rot rate of Fengyu loquat was higher than Baiyu. The modified atmosphere fresh-keeping packaging combined with 1-MCP treatment postpones the decline of nutrients and then delays the browning and senescence process of loquat during cold storage. The browning rate and membrane lipid peroxidation degree of early-maturing variety of Baiyu loquat were higher.