外源抗坏血酸和谷胱甘肽对荔枝保鲜效果的影响

Effects of ascorbic acid and glutathione treatments on litchi fruits during post harvest storage

为了探讨外源抗坏血酸(AsA)和谷胱甘肽(GSH)对荔枝保鲜效果的影响。分别在多菌灵500mg/L+施保克3mL/L+柠檬酸15.0mmol/L溶液中分别加入抗坏血酸50.0mmol/L(AsA处理)和谷胱甘肽50.0mmol/L(GSH处理)浸果5min,以多菌灵500mg/L+施保克3mL/L+柠檬酸15.0mmol/L浸果5min为对照处理,分别置于常温和6℃低温贮藏、相对湿度为80%。结果表明:AsA和GSH处理均能降低荔枝果皮多酚氧化酶(PPO)活性和相对电导率;提高果肉的超氧化物岐化酶(SOD)和过氧化氢酶(CAT)活性;降低果肉过氧化氢(H2O2)和丙二醛(MDA)的含量,维持果肉中较高的维生素C和GSH含量。低温下,AsA和GSH处理均能提高荔枝保鲜效果,降低果实的腐烂率,但AsA处理的保鲜效果要优于GSH处理的效果,而常温下GSH处理并不能提高荔枝的保鲜效果。

To investigate the effects of ascorbic acid（AsA） and glutathione（GSH） on the preservation of litchi fruits,three groups of harvested fruits were used in the experiment. Group One was immerged in a solution of 50 mmol/L ascorbic acid combined with 500 mg/L carbendazim＋3 mL/L sportak＋15 mmol/L citric acid for 5 min;Group Two in 50 mmol/L glutathione combined with 500 mg/L carbendazim＋3 mL/L sportak＋15 mmol/L citric acid for 5 min;and Group Three,as control,in 500 mg/L carbendazim＋3 mL/L sportak＋15 mmol/L citric acid for 5 min. All the samples were dried at 18℃ in the air-conditioned room. Then,each group was divided into two sub-groups：one was stored at the electric thermostat-box at 6℃ with 80% relative humidity,and the other was stored at room temperature. Compared with the control,both AsA and GSH treatments reduced the activities of PPO and the relative electric leakage in pericarp,significantly enhanced the activities of SOD,CAT and reduced the content of H2O2 and MDA in pulp. AsA and GSH treatments also increased the content of vitamin C and GSH in pulp. Both AsA and GSH treatments effectively preserved fruits in low temperature and reduced the decay rate of fruits,but AsA treatment was more effective than GSH treatment. AsA treatment was also effective in room temperature while GSH treatment was not.