4种蔬菜氧化酶、过氧化物酶活性测定及其抑制研究

Activity Determination and Inhibition of 4 Kinds of Vegetable Oxidase and Peroxidase

蔬菜多酚氧化酶(PPO)及过氧化物酶(POD)是与蔬菜货架期和防御反应相关的关键酶,PPO及POD酶活性通常被用来评价蔬菜样品的质量。研究发现,邻苯二胺(OPD)可同时作为蔬菜多酚氧化酶底物和过氧化物酶底物,蔬菜多酚氧化酶可氧化OPD产生具有荧光的2,3-二氨基吩嗪(DAP);在H_(2)O_(2)存在下,由于·OH的产生,蔬菜过氧化物酶可快速催化产生DAP。研究与经典的使用邻苯二酚氧化酶底物或愈创木酚过氧化酶底物相对比,酶活测定结果一致。基于此,文章建立了菠菜、生菜、油麦菜及马铃薯中多酚氧化酶、过氧化物酶同时测定的荧光检测新方法。同时,利用建立的方法对蔬菜酶抑制剂进行筛选,并应用于实际样品的抑制研究,结果表明筛选出的抑制剂对酶活性低的生菜和酶活性高的马铃薯均具有很好的抗褐变效果。

Vegetable polyphenol oxidase (PPO) and peroxidase (POD) are key enzymes related to vegetable shelf life and defense reactions.PPO and POD enzyme activities are usually used to evaluate the quality of vegetable samples.The studies found that o-phenylenediamine (OPD) could act as both a vegetable polyphenol oxidase substrate and a peroxidase substrate.Vegetable polyphenol oxidase could oxidize OPD to produce fluorescent 2,3-diaminophenazine (DAP);In the presence of H_(2)O_(2),vegetable peroxidase could quickly catalyze the production of DAP due to the generation of ·OH.Compared with the classic use of catechol oxidase substrate or guaiacol peroxidase substrate,the results of enzyme activity determination were consistent.Based on this,this study established a new fluorescence detection method for simultaneous determination of polyphenol oxidase and peroxidase in spinach,lettuce,lettuce,and potatoes.Meanwhile,the established method was used to screen vegetable enzyme inhibitors and applied for the inhibition study of actual samples.The results showed that the selected inhibitors had a good anti-browning effect on both lettuce with low enzyme activity and potatoes with high enzyme activity.