鲜切马铃薯多酚氧化酶酶学特性及褐变抑制剂的研究  

Study on the Polyphenol Oxidase Enzymatic Characteristics of Fresh Potato-cutting and the Inhibitor to its Browning

作　　者：刘静[1] 李湘利[1] 冯磊[1] 魏子浩[1] 殷昭起[1] 张子莹[1] 

机构地区：[1]济宁学院生命科学与工程系,山东曲阜273155

出　　处：《安徽农业科学》2009年第34期17067-17069,共3页Journal of Anhui Agricultural Sciences

基　　金：济宁学院校基金重点资助项目(2007KJ01)

摘　　要：[目的]研究常用防腐、防褐抑制剂对切分马铃薯多酚氧化酶(PPO)的抑制效果及贮运品质的影响。[方法]以无公害马铃薯为试材,以邻苯二酚为底物,采用分光光度法和正交试验法,测定马铃薯中PPO的酶学特性及不同试剂作用下PPO的活性。[结果]马铃薯PPO的最适pH值为7.6,最适温度为32℃,短时高温处理能显著抑制PPO活性;PPO催化酶促褐变反应符合米氏方程,酶促反应的最大速率(Vmax)为0.2866U/(gFW.min),米氏常数(Km)为0.032mol/L;NaHSO3、抗坏血酸能较好地抑制PPO活性,且随着浓度的升高,抑制效果增强;0.1%抗坏血酸、0.06%或0.10%CaCl2、0.08%苯甲酸钠、1.0%壳聚糖保鲜切分马铃薯丝在4℃下贮藏96h后褐变度仅为6.14%。[结论]马铃薯PPO活性受诸多因素影响,尤以pH值和温度影响最为显著;试验采用抗坏血酸等复合保鲜剂对切分马铃薯丝的褐变抑制进行了系统研究,关于不同试剂间多因素协同作用机理和抑制效应尚需做进一步研究。[ Objective ] The effect of the commonly used inhibitor to decay and brown on the polyphenol oxidase（PPO） of potato-cutting and the quality of its storage and transportation was investigated. [ Method] The non-polluted potato being taken as the testing material and the cateehol, as reacting substrate, the enzymatic property and the activity of PPO under different reagents in potato were deter mined and analyzed with the spectrophotometric method and orthogonal test, respectively. [ Results] The results showed that optimum pH value of for PPO of potato was 7.6; and the temperature, 32℃. The treatment of short-term high temperature could significantly inhibit the PPO activity. The catalytic enzyme of PPO promoting browning reaction was in line with the Miehaelis-Menten cquation, and the maximum rate of enzymatic reaction（Vmax） was 0. 286 6 U/g（ FW）/min; the Michaelis constant（Kin） was 0.032 mol/L; NaHSO3 and ascorbie acid could better inhibit the activity of PPO and as the concentration-increasing, the inhibitory effect was strengthened. Under the treatment of 0.1% aseorbic acid, 0.06% or 0. 10% CaCl2, 0.08% sodium benzoate, or 1.0% chitosan, the browning rate of fresh potato-cutting was only 6.14% after its storage for 96h at 4 ℃. [Conelusion] The activity of potato PP0 was affected by many factors, especially pH value and temperature, which effect was the most significant. The systematic research on the inhibitory effect of ascorbic acid and other compound fresh-keeping reagents on fresh potato-cutting browning was carried out and the mechanism and efficiency of the interaction among mnltiply factors in the inhibitory of fresh potato-cutting browning needed to do further study.

关 键 词：马铃薯 多酚氧化酶(PPO) 酶学特性 切分 抑制效应 

分 类 号：S532[农业科学—作物学]