低温等离子体处理减轻采后香蕉果实冷害作用的研究

研究了低温等离子体单独处理(Cold plasma treatment,CPT)和结合加湿处理(RH 90%)减轻香蕉果实冷害效果。采用峰-峰值电压20 kV,频率5 kHz介质阻挡(DBD)等离子体放电,每隔24 h对6℃低温环境下的香蕉果实贮藏环境中的气体循环处理1 min,定期取样进行冷害指数、失重率、可溶性固形物含量、硬度、乙烯含量、CO₂含量等指标的测定。结果表明:CPT能够减轻香蕉果实采后冷害的发生程度,减缓香蕉果实质量损失。相比对照组极显著(P<0.01)地降低了香蕉果实贮藏包装环境中的乙烯和CO₂的含量,从而延缓了香蕉果实在低温刺激下的后熟生理进程,增强了其对不良低温伤害的抗性。且CPT结合加湿处理效果更好,在贮藏第12 d时冷害损伤仍然较轻,失重率比对照组下降49.53%(P<0.01),同时维持较高香蕉果皮硬度。但是两种处理对香蕉果肉硬度和可溶性固形物含量变化均没有明显影响。研究结果为减轻香蕉及热带水果采后冷害提供了一种新的途径。

Effect of Cold Plasma Treatment on Alleviating Chilling Injury of Banana Fruit after Harvest

Effect of cold plasma treatment(CPT)and CPT plus humidity(RH 90%)on alleviating chilling injury of banana fruits was investigated. A dielectric barrier discharge(DBD,20 kV,5 kHz)plasma was used to treat with gas cycling in the bananas storage space at low temperature(6℃)for 1 min every 24 h. The index of cold damage,weight loss rate,soluble solid content,hardness,ethylene content,CO₂ content were determined by regular sampling. The results showed that,compared with the control,chilling injury and weight loss were relieved in CPT groups. CPT significantly(P<0.01)removed the ethylene and reduced the concentration of CO₂ in the environment of storage,consequently compared with the control,postponed the ripening progress of banana due to the stimulation of low temperature,and enhanced its capability to endure hazardous low temperature. CPT+RH demonstrated better effect on maintaining the appearance and quality of banana fruit. For CPT+RH,the chilling injury degree was lighter compared with the control on the 12th day and the weight loss rate declined by 49.53%(P<0.01).CPT+RH well kept the firmness of pericarp. However,both CPT and CPT+RH treatments did not create obvious influence on banana pulp firmness and the variation of soluble solids content. The results of this work implied that cold plasma treatment could be employed as a novel technique to relieve the chilling injury of banana and similar tropical fruits in the future.