乙烯利处理对去皮莲藕酚类和活性氧代谢的影响

Effects of ethephon treatment on phenol and active oxygen metabolism of peeled lotus root

中文关键词:  乙烯利  去皮莲藕  贮藏品质  活性氧  酚类物质

英文关键词:ethephon  peeled lotus root  storage quality  reactive oxygen species  phenolic compounds

中文摘要:

      目的 探究乙烯利(ethephon, ET)处理对去皮莲藕(Nelumbo nucifera Gaertn)贮藏品质的影响及潜在作用机制。方法 以鄂莲5号莲藕为实验材料, 每12 h测定其在20℃贮藏期间的色泽、总酚含量、多酚氧化酶(polyphenol oxidase, PPO)、苯丙氨酸解氨酶(phenylalnine ammonialyase, PAL)、超氧阴离子(superoxide production, O2–·)的产生速率、过氧化氢(hydrogen peroxide, H2O2)含量、丙二醛(malondialdehyde, MDA)含量、羟基自由基(hydroxyl radical, ·OH)生成速率、超氧化物歧化酶(superoxide dismutase, SOD)、过氧化氢酶(catalase, CAT)和过氧化物酶(peroxidase, POD)的变化规律。结果 4.0 g/L ET溶液浸泡去皮莲藕5 min有效抑制了去皮莲藕的褐变, 显著延缓了L*的下降, 在72 h贮藏后约为对照组的1.04倍(P<0.05)。在整个贮藏期间, 与对照相比, ET处理提高了PAL和PPO的活性, 诱导总酚物质含量的增加, ET处理组在60 h的总酚含量达到最高值, 其含量为165.01 mg/kg, 约为CK组的1.18倍。ET处理提高了去皮莲藕POD、SOD和CAT的活性, 同时增强了1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl, DPPH)自由基清除率。ET抑制O2–·, 降低·OH、MDA和H2O2含量。结论 4.0 g/L ET处理可以通过诱导酚类物质的生成和提高自身的抗氧化能力来延缓去皮莲藕的品质劣变, 可为维持果蔬品质方面的应用提供理论参考。

英文摘要:

      Objective To investigate the effects and possible mechanisms of ethephon (ET) on the impact of treatment on the storage quality of peeled lotus root (Nelumbo nucifera Gaertn). Methods The colour, total phenol content, polyphenol oxidase (PPO), phenylalnine ammonialyase (PAL), rates of superoxide production (O2–·), hydrogen peroxide (H2O2) content, malondialdehyde (MDA) content, hydroxyl radical (·OH), superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) were determined every 12 h during the storage period at 20℃, using E-Lian No.5 as the test material. The patterns of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and malondialdehyde (MDA) content, hydroxyl radical (·OH), superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) were determined by the results of the study. Results It was shown that soaking peeled lotus root in 4.0 g/L ET solution for 5 min effectively inhibited the browning of peeled lotus root and significantly delayed the decrease of L*, which was about 1.04 times higher than that of the control group after 72 h of storage. During the whole storage period, the ET treatment increased the activities of PAL and PPO and induced an increase in the total phenolic content compared with the control, and the total phenolic content of the ET treated group reached the highest value of 165.01 mg/kg at 60 h, which was about 1.18 times higher than that of the CK group. ET treatment increased the activities of POD, SOD and CAT in peeled lotus root, as well as enhanced 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging. ET inhibited the O2–· and reduced the content of ·OH, MDA and H2O2. Conclusion The results show that 4.0 g/L ET treatment can delay the quality deterioration of peeled lotus root by inducing the production of phenolics and improving its own antioxidant capacity, which can provide theoretical references for applications in maintaining the quality of fruits and vegetables.