采前草酸处理对西兰花采后保鲜效果及抗氧化特性的影响

Effects of pre-harvest oxalic acid treatment on preservation effect and antioxidant capacity of post-harvest Brassica oleracea var.italica

旨在研究采前喷洒草酸水溶液处理对西兰花(Brassica oleracea var.italica)采后抗氧化特性的影响,从而评价草酸处理对西兰花衰老的调控作用。结果表明,采前用20 mmol/L草酸水溶液处理西兰花可显著抑制采后西兰花丙二醛(MDA)的积累和细胞膜透性的增加(P<0.05),还可以诱导采后西兰花超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性的增强,抑制采后西兰花超氧阴离子自由基(O2·-)的生成速率和过氧化氢(H2O2)含量的上升,显著提高采后西兰花对1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基的清除能力(P<0.05)。采前喷洒草酸水溶液处理可有效维持采后西兰花活性氧代谢平衡,维持其细胞膜的完整性,进而延缓西兰花采后的衰老进程,延长其贮藏期。

The effect of pre-harvest treatment of spraying oxalic acid(OA)aqueous solution on the antioxidant activity of post-harvest Brassica oleracea var.italica was investigated to evaluate the regulatory effect of OA treatment on the senescence of B.oleracea var.italica.The results showed that pre-harvest treatment with 20 mmol/L OA aqueous solution significantly inhibited the accumulation of malondialdehyde(MDA)and the increase of cell membrane permeability in post-harvest B.oleracea var.italica(P<0.05).Meanwhile,activities of superoxide dismutase(SOD)and catalase(CAT)were enhanced,generation rate of superoxide anion radical(O·-2)and the increase of H2O2 content were inhibited,and the scavenging activity of 1,1-diphenyl-2-picrylhydrazyl(DPPH)radical was significantly enhanced under pre-harvest treatment of OA aqueous solution.Pre-harvest treatment of spraying OA aqueous solution can maintain the balance of active oxygen metabolism effectively,keep the integrity of cell membrane,so as to delay the senescence process and prolong the shelf life of post-harvest B.oleracea var.italica.