Abstract:

The characteristic of potato tubers browning seriously affect the quality of processed products and the development of processing industry. In this study，the browning-degree（BD），polyphenol oxidase（PPO），peroxidase（POD），total phenol content of fifty potato varieties were measured to investigate the relationship between enzymatic browning of tubers and PPO，POD，total phenol content by using the methods of correlation analysis，cluster analysis，and membership function. The results showed that the BD of potato tubers was significantly correlated with PPO and POD activity，but not with total phenol content. Furthermore，fifty potato varieties（lines）were divided into four types：Ⅰ（Highly browning-susceptible，HS）included one variety；Ⅱ（Browning-susceptible，BS），included nineteen varieties；Ⅲ（Middle browning-susceptible，MS），included fifteen varieties；Ⅳ（Browning-resistance，R），included fifteen varieties. Most varieties are browning-susceptible. Of all，‘Xingjia 2’and‘Jizhang 8’belonging to highly browning-resistance type，which could be used as browning-resistant resource for genetic breeding.‘Dianshu 6’belonged to highly browning-susceptible type. It could be used as a good material for the study of enzymatic browning mechanism.

Key words: potato, enzymatic browning, polyphenol oxidase, peroxidase, correlation analysis, cluster analysis