红三叶、苜蓿青贮前后蛋白质的变化

Protein Changes in Red Clover and Alfalfa Herbage and Silage

红三叶与苜蓿有着相近的蛋白质含量和相似的青贮特性,但在青贮后苜蓿中的蛋白质发生大量水解,非蛋白氮的增加量比红三叶高出近一倍,非蛋白氮的组成也产生了一定差异。造成这种差异的原因是红三叶中含有一种多酚氧化酶,它催化植物中的酚类物质生成苯醌,苯醌与蛋白质发生聚合反应从而起到保护蛋白的作用。

Red clover and alfalfa had the similar protein content and ensiling characteristics.But extensive proteolysis of ensiled alfalfa has occurred during fermentation,and the increase of NPN was more than that of red clover by one time.The composition of the NPN also been altered.The main reason of this difference was that red clover had a soluble polyphenol oxidase(PPO) and PPO oxidized native phenols into quinines which bond to protein and inhibited proteolysis.