贮前强制对流热空气处理对低温胁迫下青椒果实AsA-GSH循环代谢的影响

Effects of pre-storage forced convective hot air treatment on AsA-GSH cycle of green pepper in low temperature stress

该文以青椒果实为试材,采用50℃强制对流热空气下处理5、10、20、30、40 min,并以不经任何处理的青椒果实为对照进行研究。结果表明,较对照组和其他强制对流热空气组,50℃强制对流热空气处理20 min能够推迟冷藏青椒果实的冷害发生时间,维持显著高于(P<0.05)对照组的叶绿素和可滴定酸含量。同时该组青椒果实的电解质外渗率、丙二醛(malondialdehyde,MDA)、H 2O 2以及超氧阴离子自由基(O2^-·)都维持在显著低于(P<0.05)对照组水平,抗坏血酸(ascorbic acid,AsA)和还原型谷胱甘肽(reduced glutathione,GSH)的含量以及抗坏血酸过氧化物酶(ascorbate peroxidase,APX)和谷胱甘肽还原酶(glutathione reductase,GR)活性也较对照得到了显著高水平(P<0.05)的保持,能有效减轻低温胁迫下活性氧对细胞的伤害,延缓了青椒果实的冷害。该研究为青椒果实贮藏保鲜、揭示采后果蔬热应激在低温胁迫下的抗冷性响应机制提供理论依据。

This research aimed to study the effects of forced convective hot air treatment on AsA-GSH cycle and the resistance of green pepper fruit to low temperature stress.The green pepper fruits were treated with 50℃forced convection hot air for 5,10,20,30 and 40 min,while those without any treatment were used as control.It was found that forced convection hot air treatment at 50℃for 20 min showed best results on delaying the occurrence of chilling injury of the frozen green pepper fruit and maintained significantly higher chlorophyll and titratable acid content than control group(P<0.05).At the same time,the electrolyte leakage rate,malondialdehyde(MDA),H2O2 and superoxide anion(O2^-)of the green pepper fruits were significantly lower than those in the control group(P<0.05).The contents of ascorbic acid(AsA)and reduced glutathione(GSH)as well as the activities of ascorbic peroxidase(APX)and glutathione reductase(GR)were also significantly lower than those in the control group(P<0.05).The results revealed that forced convection hot air treatment could effectively reduce the damage of reactive oxygen species(ROS)to cells under low temperature stress and delay the chilling injury of green pepper fruits,which provides a theoretical basis for the storage and preservation of green pepper fruits and for the response mechanism to cold stress in post-harvest vegetables.