草酸处理对桂七芒果冷害及细胞壁代谢的影响

为探讨草酸处理对低温冷藏下芒果冷害及细胞壁代谢的影响,本试验以桂七芒果果实为试材,采用5 mmol·L^-1草酸溶液浸泡处理,以清水浸泡处理为对照,并于4℃贮藏,分析芒果的冷害指数、丙二醛(MDA)含量、相对电导率、硬度、细胞壁物质含量、细胞壁代谢酶的变化。结果表明,与对照组相比,草酸处理显著降低了低温贮藏14 d后桂七芒果果实冷害指数、MDA含量、相对电导率、原果胶和纤维素含量,显著降低了低温贮藏28 d后果实的硬度;显著提高了低温贮藏14 d后果实水溶性果胶含量及多聚半乳糖醛酸酶(PG)、果胶甲酯酶(PME)、纤维素酶(Cx)活性,显著提高了贮藏21 d后果实β-半乳糖苷酶(β-Gal)活性。综上所述,草酸处理能减轻桂七芒果冷害,维持采后果实细胞壁降解酶较高活性和水溶性果胶含量。本研究为揭示草酸减轻芒果果实冷害机制提供了依据,可为草酸应用于其他冷敏型果实的贮藏保鲜提供理论参考。

Effect of Oxalic Acid Treatment on Chilling Injury and Cell Wall Metabolism of Guiqi Mango

To investigate the effect of oxalic acid treatment on chilling injury and cell wall metabolism of Guiqi mango fruit under low temperature storage, Guiqi mangoes were dipped in 5 mmol·L^-1 oxalic acid solution and dipped in water as control, then stored at 4℃, and the changes in chilling injury index, MDA content, relative conductivity, firmness, cell wall components, activities of cell wall metabolize enzymes were analyzed during storage. The results showed that oxalic acid treatment significantly reduced chilling injury index, MDA content, relative conductivity propectin and cellulose content of Guiqi mango after low temperature storage for 14 days,and significantly reduced the fruit hardness after low temperature storage for 28 days , while obviously increased the water soluble pectin content and the activities of polygalacturonase (PG), pectin methyl enzyme (PME), and cellulase (Cx) after low temperature storage for 14 days, and significantly increased the activities of β-galactose glucoside enzyme (β-Gal) after low temperature storage for 21 days. It suggested that oxalic acid treatment could alleviate chilling injury in Guiqi mango, and maintain high activities of degradation enzymes in cell wall and high water soluble pectin content. The results of this study could provide a theoretical basis for revealing the mechanism of oxalic acid reducing chilling injury of mango fruits, as well as a theoretical reference for the application of oxalic acid to the storage and preservation of other cold-sensitive fruits.