Abstract: The enzymatic browning and its main substrates in fresh-cut lotus roots were studied during storage period. The results were as followsing: The newly synthesized phenolic substances were mainly the FP, which were the primary phenols catalyzed by PPO to cause browning; The changes of free phenols (FP) and browning degree (BD) after 6 days storage had significantly negative relationship (r=0.959); The FP, catechol and PPO activity showed the synchronous change pattern which increased first and decreased afterwards；The content of catechol in Fresh-cut lotus roots measured by thin layer chromatography and HPLC decreased significantly after browning; The absorption spectrums of catalytic product of catechol and browning product in fresh-cut lotus roots are identical, and Catechol therefore was considered as the major browning substrate in fresh-cut lotus roots.

Key words: Fresh-cut lotus roots , Enzymatic browning , Free phenols , Catechol