气调贮藏对茭白抗氧化系统的影响

Effects of Controlled Atmosphere on Antioxidation System of Water Bamboo

为探究气调处理对茭白抗氧化相关生理机制,以空气为对照(CK),于0℃、相对湿度85%~90%的贮藏环境下,研究4种不同气体组分(CA1(2%O_(2)+7%CO_(2))、CA2(5%O_(2)+10%CO_(2))、CA3(5%O_(2)+7%CO_(2))、CA4(2%O_(2)+10%CO_(2)))对茭白采后抗坏血酸(Vc)、总酚、自由基(DPPH、羟基自由基)清除率、丙二醛(MDA)、相对电导率、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性的影响。结果表明:气调处理不同程度地延缓了Vc、总酚含量的下降,抑制MDA和相对电导率的上升,维持较高的DPPH、羟基自由基清除率以及SOD、CAT、POD活性。贮藏至结束,CA2组茭白Vc、总酚、DPPH和羟基自由基清除率分别较CK高63.58%、10.17%、91.25%和59.17%,MDA、相对电导率分别较CK低43.02%、74.53%,SOD活性显著高于CK(P<0.05),CAT和POD活性极显著高于CK(P<0.01)。综上可知,CA2(5%O_(2)+10%CO_(2))处理加快了自由基清除速率,减轻膜脂过氧化,从而延缓了茭白衰老。

In order to study the effect of different controlled atmosphere treatments(CA1(2%O_(2)+7%CO_(2)),CA2(5%O_(2)+10%CO_(2)),CA3(5%O,+7%CO_(2)),CA4(2%O_(2)+10%CO_(2)))on the antioxidant of water bamboo,the water bamboo were stored at 0℃with the relative humidity(RH)of 85%~90%.The Vc content,total phenols,free radical(DPPH,hydroxyl radical)scavenging rate,MDA,relative electric conductivity,the activities of SOD,CAT and POD were analyzed.The results showed that the controlled atmosphere treatments delayed the decrease of Vc content and total phenols,inhibited the increase of MDA and relative electric conductivity,maintained a high DPPH,hydroxyl radical scavenging rate,and high SOD,CAT and POD activities.After 90 d of storage,the CA2 treatment had higher Vc and total phenols content,DPPH and hydroxyl radical scavenging rate(increased by 63.58%,10.17%,91.25%and 59.17%,respectively),and lower MDA content and relative electric conductivity(decreased by 43.02%and 74.53%,respectively),the activity of SOD was lower than that in the CK(P<0.05),the activities of CAT and POD were significantly lower than that in the CK(P<0.01).The above results showed that the CA2 treatment could effectively scavenge free radicals and reduce the membrane lipid peroxidation,thus delaying the senescence of postharvest waterbamboo.