Abstract: The activities of phenylalanine ammonialyase (PAL), peroxidase (POD) and polyphenol oxidase (PPO) and the contents of malondialdehyde (MDA), polyphenol and lignin in fresh-cut bamboo shoots stored at 4 ℃ were measured and the lignification mechanism was explored. The results indicated that the activities of PAL and POD and MDA content tended to increase and then decrease with increasing storage time. PPO activity slowly ascended during the first 6 days, and began to descend on the 15th day, whereas polyphenol content sharply declined during the first 6 days, then slow rose, and began to decline again on the 12th day. Lignin content showed a continuous increase, which was 5%－26% in the bottom, 3%－24% in the middle and 2%－22% in the top. These data suggest that the activities of PAL and POD considerably increase during cold storage, which are the key enzymes in the lignification of fresh-cut bamboo shoots. Moreover, phenolic compounds are involved in the synthesis of lignin by providing precursors. Meanwhile, MDA may also be involved in the lignification of fresh-cut bamboo shoots, which needs further identification. Lignin content gradually decreases from the bottom to the top of bamboo shoots, implying the lignification process proceeds from the bottom to the top.

Key words: fresh-cut bamboo shoots, cold storage, phenylalanine aminolyase, peroxidase, lignification