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氯吡苯脲处理对莲子细胞壁多糖 降解特性的影响

孙凤杰1,罗淑芬2,颜廷才3,胡花丽4,周宏胜2,张雷刚2,李鹏霞5   

  1. 1. 江苏省农业科学院农产品加工所;沈阳农业大学食品学院
    2. 江苏省农业科学院农产品加工所
    3. 沈阳农业大学食品学院
    4. 江苏省农业科学院
    5. 江苏省农业科学院农产品加工研究所
  • 收稿日期:2018-01-02 修回日期:2018-12-19 出版日期:2019-03-15 发布日期:2019-04-02
  • 通讯作者: 李鹏霞 E-mail:guoshubaoxian@163.com
  • 基金资助:
    江苏省农业科技自主创新资金

Effects of CPPU Treatment on Degradation Characteristics of Cell Wall Polysaccharides of Lotus Seeds

1, 1, Hu huali 1,gang leizhang1,Pengxia Li   

  • Received:2018-01-02 Revised:2018-12-19 Online:2019-03-15 Published:2019-04-02
  • Contact: Pengxia Li E-mail:guoshubaoxian@163.com

摘要: 为探究氯吡苯脲[1-(2-chloropyridin-4-yl)-3-phenylurea,CPPU]处理对莲子采后细胞壁多糖降解特性的影响,以“太空莲36号”莲蓬为试材,以清水浸泡为对照,以5 mg/L CPPU对莲蓬进行处理。首先,实验得出CPPU处理可有效维持莲蓬及莲子较好的表型,保持莲子脆嫩口感;同时,莲子细胞壁物质的红外分析结果显示,该处理的莲子含有更高的果胶物质含量和更完整的纤维素多糖碳链结构。在此基础上,试验进一步研究了CPPU处理对莲子细胞壁多糖含量和相关酶活性,以及细胞壁和纤维素微纤丝超微结构的影响。结果表明:CPPU处理可有效抑制果胶甲酯酶、多聚半乳糖醛酸酶等果胶降解酶和外切葡聚糖酶、β-葡萄糖苷酶、内切葡聚糖酶等纤维素降解酶的活性,从而延缓共价结合果胶降解及水溶性和离子结合果胶积累,并保持莲子纤维素和半纤维素含量;同时,CPPU处理保持了莲子细胞壁结构和纤维素微纤丝的形态,并抑制了其细胞的质壁分离。因此,CPPU处理有利于抑制莲子细胞壁多糖的降解,更好地维持细胞完整性,保持莲子的口感,从而延缓其采后衰老,为鲜莲蓬和莲子的采后保鲜提供理论依据和技术支持。

关键词: 莲蓬, 氯吡苯脲, 贮藏品质, 细胞壁多糖, 超微结构

Abstract: In order to investigate the effect of 1-(2-chloropyridin-4-yl)-3-phenylurea (CPPU) treatment on the degradation of the cell wall polysaccharides of lotus seeds, the harvested lotus pods were treated with 5 mg/L of CPPU. The sample treated with distilled water was used as control. Firstly, it was found that when compared with control, CPPU treatment significantly maintained good phenotype of lotus pods and seeds, as well as crisp and tender taste of the seeds. Meanwhile, FTIR results showed that CPPU treatment exhibited good effect on keeping pectin content and the carbon chain of cellulose polysaccharide in lotus seeds cell wall. On this basis, we further studied the effect of CPPU treatment on the content of polysaccharide and related enzymes activities in lotus seeds, ultrastructure of cell wall and cellulose microfibrils. The results showed that CPPU treatment inhibited the activities of pectin-degrading enzymes such as pectinesterase (PE) and polygalacturonase (PG), and the activities of cellulose-degrading enzymes such as cellobiohydrolase 1 (C1), β-1,4-endoglucanase (Cx) and β-glucosidase. Thus, the lotus seeds in treated sample possessed higher contents of cellulose and hemicellulose, and covalent-soluble pectin of the seeds were inhibited by CPPU treatment, resulting in less accumulation of water-soluble pectin and ionic-soluble pectin. At the same time, the results of the cell wall ultrastructure showed that the degradation of cell wall and cellulose microfibrils, and the incidences of cellular plasmolysis of the seeds were retarded by CPPU treatment. Therefore, CPPU treatment is beneficial for delaying the degradation of cell wall polysaccharides and maintaining the cell integrality of lotus seeds, and thus slowing down the senescence of lotus pods and seeds, which provided theoretical and technical support for postharvest storage of lotus pods and seeds.

Key words: lotus pods, CPPU, storage quality, cell wall polysaccharides, ultrastructure