曹州木瓜过氧化物酶酶学特性研究  

Characterization of Peroxidase from Caozhou Chaenomeles Fruits

作　　者：隋园园[1] 董海洲[1] 王兆升[1] 李钟涛[2] 程春牛 

机构地区：[1]山东农业大学食品科学与工程学院山东泰安271018 [2]安丘市农业局山东安丘262100 [3]菏泽市木瓜研究所山东菏泽274000

出　　处：《中国食品学报》2014年第6期68-73,共6页Journal of Chinese Institute Of Food Science and Technology

基　　金：菏泽市科学技术计划项目(111D656098)

摘　　要：以曹州木瓜果实为试验材料,采用分光光度法对曹州木瓜过氧化物酶(POD)的酶学特性进行研究,为控制木瓜加工贮藏过程中的酶促褐变提供理论依据。试验结果表明:曹州木瓜POD的最适pH 5.8,最适反应温度45℃,90℃处理75 s或者100℃处理30 s后POD活性完全丧失。其过氧化物酶催化的酶促褐变反应动力学符合米氏方程,动力学参数Km=18.17 mmol/L,Vmax=1 666.67 U。抑制剂对POD的抑制作用从大到小依次为VC>亚硫酸氢钠>柠檬酸>EDTA-2Na。Na+,K+,Mg2+,Mn2+和Ca2+对POD具有激活作用,Zn2+,Ba2+和Cu2+在低浓度时对POD有激活作用,高浓度时有抑制作用。In this study, the enzymatic characteristics of the peroxidase （POD） from Caozhou Chaenomeles sinensis were investigated by spectrophotometer method with the purpose of contributing a theoretical basis for protecting Caozhou Chaenomeles sinensis from enzymatic browning in the course of processing and storage. The results showed that the POD has an optimum pH of 5.8 and temperature of 45 ℃, and it was completely inactivated when incubated at 90 ℃ for 75 s or 100 ℃ for 30 s. The kinetics of the POD -catalyzed browning reaction was in accord with Michaelis-Menten equation, with the Km and Vmax values of 18.17 mmol/L and 1 666.67 U using guaiacol as substrate, respectively. Four inhibitors demonstrated different effects on POD activity, and their inhibitory capacity was decreased in the order： ascorbic acid〉 NaHSO3〉citric acid〉EDTA-2Na. The POD showed enhanced activity in presence of Na＋, K＋, Mg^2＋, Mn2＋ and Ca2＋. Zn^2＋, Ba^2＋ and Cu^2＋ activated POD activity at lower concentrations （-1 mmol/L） whereas inhibited the activity at higher concentrations （-10 mmol/L）.

关 键 词：农产品 光皮木瓜 过氧化物酶 酶学特性 

分 类 号：S661.6[农业科学—果树学]