氯吡苯脲处理对采后莲蓬保鲜效果的影响

Effect of 1-(2-Chloropyridin-4-yl)-3-phenylurea(CPPU) Treatment on the Postharvest Quality of Lotus Pods

为探索采后莲蓬保鲜新方法,选用‘太空莲36号’为试材,首先以不同质量浓度(2.5、5.0、10.0、15.0、20.0 mg/L)氯吡苯脲(1-(2-chloropyridin-4-yl)-3-phenylurea,CPPU)对莲蓬进行处理,以莲蓬及莲子感官品质、莲皮色差、莲子蛋白含量为依据,筛选出最佳的莲蓬处理质量浓度;然后,以不作处理(CK0)和清水浸泡(CK1)作对照,在(25±1)℃贮藏条件下,研究了CPPU处理对鲜莲蓬呼吸作用及鲜莲子褐变度、可溶性固形物质量分数和淀粉含量、丙二醛(malondialdehyde,MDA)和过氧化氢(hydrogen peroxide,H_2O_2)含量、超氧阴离子自由基(superoxide anion radical,O_2^-·)生成速率及超氧化物歧化酶(superoxide dismutase,SOD)、过氧化氢酶(catalase,CAT)、过氧化物酶(peroxidase,POD)和多酚氧化酶(polyphenol oxidase,PPO)活力的影响。结果表明:CPPU处理莲蓬的最佳质量浓度为5.0 mg/L,CPPU处理可有效防止莲蓬及莲子褐变,维持莲蓬和莲子较好的表型,并抑制莲蓬呼吸作用,减少莲子可溶性固形物积累和淀粉消耗,减小O_2^-·生成速率和H_2O_2、MDA等的累积,同时与对照组相比,能维持较高的SOD、CAT活力,抑制POD、PPO活力。此外,经CPPU处理后,莲子中CPPU残留量低于国家标准。综上所述,CPPU处理有利于提高采后莲蓬及莲子贮藏品质,是采后鲜莲蓬贮藏保鲜的一种新方法。

In order to explore a new method for the preservation of fresh lotus pods,the harvested lotus pods were treated with different concentrations(2.5,5.0,10.0,15.0,and 20.0 mg/L)of 1-(2-chloropyridin-4-yl)-3-phenylurea(CPPU).By analyzing the sensory qualities of lotus pods and seeds,the color difference of lotus seed coats and the protein content of lotus seeds,the optimal concentration of CPPU was selected for the following experiments.Lotus pods without any treatment and those treated with distilled water were used as controls(CK0 and CK1).Then,the effect of CPPU treatment on browning degree,total soluble solids content,starch content,malondialdehyde(MDA)content,hydrogen peroxide(H2O2)content,the rate of superoxide anion radical(O2^-·)generation,super oxide dismutase(SOD)activity,catalase(CAT)activity,peroxidase(POD)activity and polyphenol oxidase(PPO)activity of lotus seeds were investigated during storage at(25±1)℃.The results showed that the optimal concentration was 5.0 mg/L,and that CPPU treatment effectively prevented the browning of both lotus pods and seeds,maintaining desirable appearance,and inhibited the respiration rate of lotus pods.Moreover,this treatment inhibited the accumulation of soluble solids and starch depletion and lowered the rate of O^2-·generation and the accumulation of H2O2 and MDA.The activities of SOD and CAT were significantly improved,and the activities of POD and PPO were inhibited by CPPU treatment.In addition,the CPPU residue in CPPU-treated lotus seeds was lower than the Chinese national standard limit.Therefore,CPPU treatment is useful for improving postharvest storage quality and delaying senescence of lotus pods and seeds,and will be a promising method for extending the storage life of lotus pods.