烤烟中多酚氧化酶促褐变反应抑制剂的筛选

Screening of Inhibitors Against Browning Reaction Induced by Polyphenol Oxidase in Flue-cured Tobacco

为解决调制、加工过程中烟叶颜色过度转深问题,进行了用柠檬酸、硼酸、二乙基二硫代氨基甲酸钠(NaDDC)、乙二胺四乙酸(EDTA)、聚乙烯吡咯烷酮(PVP)、l-半胱氨酸、抗坏血酸(Vc)和硫脲在磷酸盐缓冲溶液中抑制烤烟烟叶多酚氧化酶(PPO)活性试验。结果表明:①PVP(1.0mmol/L)、l-半胱氨酸(0.6mmol/L)、Vc(1.0mmol/L)和硫脲(3.2mmol/L)均能有效抑制缓冲液中多酚氧化酶的活性;②1.0mmol/LPVP+3.0mmol/L硫脲+0.75mmol/LVc+0.375mmol/Ll-半胱氨酸或3.0mmol/L硫脲+0.75mmol/LVc+0.375mmol/Ll-半胱氨酸复合制剂的抑制效果较佳。

In order to prevent flue-cured tobacco leaf from darkening in the course of curing and processing, the experiments on inhibiting polypheuol oxidase （PPO） activity in flue-cured tobacco with citric acid, boric acid, sodium diethyl disulphocarbamate （NaDDC）, ethylene diamiuo tetracetic acid （EDTA）, polyvinyl pyrrolidone （PVP）, l - cysteine, ascorbic acid （Vc）, and thiourea in phosphate buffer solution were conducted. The results showed that： 1 ） the PPO activity in phosphate buffer solution was effectively inhibited by PVP （1.0 retool/L） , l- cysteine （0.6 mmol/L） , Vc （1.0 mmol/L） or thiourea （3.2 mmol/L） ; 2） the mixture of PVP （1.0 retool/L） ＋ thiourea （3.0 retool/L） ＋ Vc （0.75 retool/L） ＋ l-cysteine （0.375 retool/L） or the mixture of thiourea, Vc and I - cysteine was more effective.