乙醇熏蒸处理对鲜切莲藕片褐变和活性氧代谢的影响

Effects of Ethanol Vapor Treatment on Browning and Reactive Oxygen Species Metabolism of Fresh-cut Lotus Root Slices

褐变是导致鲜切莲藕品质劣变的重要因素,本文选用150μL/L乙醇熏蒸处理鲜切莲藕2 h,研究乙醇对其酶促褐变和活性氧代谢的影响。结果表明,经过10℃下贮藏12 d后,与对照组相比,乙醇处理后的鲜切藕片褐变度降低了6.49%,L^(*)值提高了21.44%。乙醇处理也能通过抑制苯丙氨酸解氨酶和多酚氧化酶活力来抑制鲜切莲藕酚类物质的合成及氧化。在贮藏末期,对照组的可溶性醌含量是乙醇处理组的1.15倍。此外,乙醇处理可有效维持过氧化氢酶和过氧化物酶活性和抗坏血酸含量。经过12 d的贮藏后,乙醇处理后的鲜切莲藕的O_(2)^(-)·生成速率和H_(2)O_(2) 积累分别是对照组的87.69%和79.17%。综上,乙醇熏蒸处理可能通过抑制酚类物质代谢,提高抗氧化能力,从而延缓鲜切莲藕褐变的发生。

Browning is an important factor contributing to the quality deterioration of fresh-cut lotus roots.In this study,150μL/L ethanol fumigation for 2 h was employed to investigate the effects of ethanol on the enzymatic browning and reactive oxygen metabolism of fresh-cut lotus root slices.The results showed that after storage at 10℃for 12 d,the browning degree and L^(*)value of fresh-cut lotus root slices decreased by 6.49%and increased by 21.44%,respectively,after ethanol treatment,compared with the control group.Ethanol treatment also could suppress the synthesis and oxidation of phenols in fresh-cut lotus roots by inhibiting phenylalanine deaminase and polyphenol oxidase activities.By the end of storage,the soluble quinone content of the control group was 1.15 folds as that of the ethanol-treated group.In addition,ethanol treatment could effectively maintain catalase and peroxidase activities and ascorbic acid content.After 12 d of storage,the O_(2)^(-)·production rate and H_(2)O_(2) level in fresh-cut lotus roots after ethanol treatment were 87.69% and 79.17%of those in the control group,respectively.In conclusion,ethanol fumigation treatment may delay the occurrence of browning in fresh-cut lotus roots by inhibiting phenolic metabolism and increasing antioxidant ability.