间歇热处理对柑橘冷害调控研究

Regulation of Cold Damage of Citrus by Intermittent Heat Treatment

目的针对柑橘低温贮藏易冷害问题,研究间歇热处理对柑橘冷害的调控效果。方法以浙江省衢州市沃柑品种为实验材料,采用连续热处理(50℃下热水处理180 s)和间歇热处理(50℃下热水处理60 s—20℃常温下回温10 min—50℃下热水处理60 s—20℃常温下回温10 min—50℃下热水处理60 s—20℃常温下回温10 min)等2种方式处理柑橘。结果与对照组相比,热处理能够降低柑橘的冷害指数,抑制相对电导率和丙二醛(MDA)含量的上升,提高柑橘的过氧化物酶(POD)和超氧化物歧化酶(SOD)活性,且间歇热处理组柑橘的抗冷效果显著优于连续热处理组(P<0.05)。贮藏50 d后,间歇热处理组的冷害指数比对照组低19.32%,MDA质量摩尔浓度分别比对照组和连续热处理组低0.91μmol/g和0.37μmol/g,POD活性分别较对照组和连续热处理组增加了0.72倍和0.19倍,SOD活性分别比对照组和连续热处理组增加5.231 U/g和1.776 U/g。结论热处理能够延缓柑橘冷害,且间歇热处理对沃柑的保鲜效果优于连续热处理。

The work aims to study the regulation effect of intermittent heat treatment on the citrus cold damage aiming at the problem of cold damage in the low temperature storage of citrus.The Quzhou bergamot varieties in Zhejiang Province were used as experimental materials.Continuous heat treatment(50℃hot water treatment for 180 s)and intermittent heat treatment(50℃hot water treatment for 60 s—temperature returning at 20℃room temperature for 10 min—50℃hot water treatment for 60 s—temperature returning at 20℃room temperature for 10 min—50℃hot water treatment for 60 s—temperature returning at 20℃room temperature for 10 min)were used to treat citrus.Compared with the control group,heat treatment could reduce the cold damage index of citrus,inhibit the increase of relative conductivity and malondialdehyde(MDA)content,and increase the activity of citrus peroxidase(POD)and superoxide dismutase(SOD),and the cold resistance effect of citrus subject to the intermittent heat treatment was significantly better than that of continuous heat treatment(P<0.05).After 50 days of storage,the cold damage index of intermittent heat treatment was reduced by 19.32%compared with the control group,and the MDA content respectively decreased 0.91μmol/g and 0.37μmol/g compared with the control group and continuous heat treatment.POD activity increased by 0.72 times and 0.19 times compared with control group and continuous heat treatment,and SOD activity was higher than that of control group and continuous heat treatment by 5.231 U/g and 1.776 U/g,respectively.Heat treatment can delay the cold damage of citrus,and the fresh-keeping effect of intermittent heat treatment on the bergamot is better than continuous heat treatment.