摘要
在批把果肉酚酶提取分离的基础上,对酚酶的适宜pH条件和热稳定性以及对几种抑制物质的反应作了探索,结果表明酶A、酶B的最适pH范围分别为4.2～4.7和5.8～6.5,两种酶在pH6.5～7时较为稳定、酚酶具有较强的耐热性,当60～70℃时酚酶仍有较高的活力和较好的稳定性.抗坏血酸、苯式硫脲、亚硫酸氢钠、DT T(二硫赤苏糖酵)对酶A、B都有不同程度的抑制作用。0.05mmol/L铜试剂对酶B有显著的抑制作用,而对酶A的作用不明显,EDTA对酶B基本上无抑制作用。
The enzyme A and enzyme B were extracted, separated and purified from loquat flesh (Eribotrya japoni-
ca Lind). The optimum pH range of the enzyme A and enzyme B were 4.2～4.7 and 5.8～6.5, respectively-
Both were stable at pH 3.5～7.0. Heat stability test showed that both enzymes were very active and stable at
temperatutes as high as 60 to 70℃. While at 80℃, the emzymes were inactivated within ten minutes. In-
hibitors like sodium sulfite, L-ascorbic acid, dithiothreitol(DTT), thiurea, phenylthiourea showed inhibition
towards both enzyme under 0.05～0.25mmol/L concentrations. About 0.05mmol/L diethyldithiocarbamate
can inhibit enzyme B while it showed no inhibition towards enzyme A. EDTA had no sign of inhibition to-
wards both enzymes.
出处
《科技通报》
1993年第1期50-54,共5页
Bulletin of Science and Technology
关键词
枇杷
多酚氧化酶
抑制剂
温度
loquat fruit
polyphenol oxidase
inhibitor
temperature
