香椿冷藏期间酚类物质及相关酶活性的变化

Changes of Phenolic Substances and Related Enzymes in Shoots of Toona Sinensis during 0℃ Storage

新鲜香椿挑选整理后于0℃下贮藏。贮藏期间定期测定香椿中总酚(TP)和游离酚(FP)的含量、多酚氧化酶(PPO)和过氧化物酶(POD)的活性。结果表明香椿总酚中以结合酚为主,只有约1/3左右是FP;贮藏的3～6dTP含量稍有增加,以后保持稳定,后期有下降且速度较快;结合酚(BP)的变化趋势与TP相似;而FP含量贮藏前期有一定增加,后期基本保持稳定。PPO和POD的活性贮藏期间均缓慢增加,在贮期结束时大幅度上升。

The selected fresh Toona Sinensis shoots were stored at 0℃.The contents of total phenol(TP) and free phenol(FP),and the activities of, PPO (Polyphenoloxdases and POD(Pexoxidase) were determined periodically during storage. The resultswere as follows: TP, mainly BP (boundphend)and FP, was only about 1/3. The content of TP increased slowly from 3 to 6d ofstorage and decreased rapidly at the end stage of storage. The changes of BP showed the same tendency like TP, while FPincreased a little in the early stage of storage and then did not change much up to the end of storage. The activities of PPO andPOD increased not much at the first 12d of storage and increased sharply afterwards.