低温等离子体处理对鲜切胡萝卜品质及抗氧化活性的影响

Effect of cold plasma on quality and antioxidant activityin fresh-cut carrot

[目的]本文旨在研究低温等离子体处理对鲜切胡萝卜贮藏期间品质及抗氧化活性影响,为低温等离子体处理在鲜切胡萝卜保鲜中的应用提供依据。[方法]将鲜切胡萝卜用介质阻挡放电型低温等离子体在60 kV下处理5 min,于(10±1)℃下贮藏72 h,定期取样测定其品质指标、多酚含量及抗氧化活性。[结果]低温等离子体处理可抑制鲜切胡萝卜过氧化物酶活性的升高及木质素的积累,延缓白变的发生,同时显著抑制微生物的生长,保持较高的抗坏血酸和总胡萝卜素含量。此外,低温等离子体处理可提高鲜切胡萝卜贮藏前期超氧阴离子生成速率及过氧化氢含量,提高苯丙烷代谢关键酶苯丙氨酸解氨酶(PAL)、肉桂酸-4-羟化酶(C4H)及4-香豆酸辅酶A连接酶(4CL)的活性,以及绿原酸、咖啡酸等酚类物质含量和1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除率。[结论]低温等离子体处理可有效延缓鲜切胡萝卜品质劣变,促进酚类物质积累,增强鲜切胡萝卜的抗氧化能力。

[Objectives]The paper aimed to investigate the effects of cold plasma treatment on the quality and antioxidant activity of fresh-cut carrots during storage,and to propose a basis for the application of cold plasma treatment in fresh-cut carrot preservation.[Methods]Fresh-cut carrots were treated with dielectric barrier discharge cold plasma at 60 kV for 5 min and stored at(10±1)℃for 72 h.Regular samples were taken to measure the quality parameters,polyphenols content and antioxidant activity of fresh-cut carrots.[Results]Cold plasma treatment could slow down the occurrence of white blush by inhibiting peroxidase activity and the accumulation of lignin and inhibit the growth of surface microorganisms in fresh-cut carrots.Cold plasma treatment maintained higher contents of ascorbic acid and total carotenoid in fresh-cut carrots.In addition,cold plasma treatment could improve the generation rate of O·-2 and H 2O 2 content during the early storage period,and improve the activities of phenylalanine ammonialyase(PAL),cinnamic acid 4-hydroxylase(C4H)and 4-coumaric acid coenzyme A ligase(4CL),and improve the contents of chlorogenic acid,caffeic acid and other phenolic substances and 1,1-diphenyl-2-picrylhydrazyl(DPPH)radical scavenging rate in fresh-cut carrots.[Conclusions]Cold plasma treatment could delay the quality deterioration of fresh-cut carrots,and improve the antioxidant activity by promoting the accumulation of phenolic substances.