Abstract: Using the twigs and petioles of Actinidia arguta var. purpurea as test materials, the polyphenol oxidase (PPO), total phenol content, and their change pattern were analyzed. The results showed that, the suitable pH value for determining A. arguta var. purpurea PPO activity was 7.0, the optimal substrate was oxophenic acid, with the concent of 0.16 mol/L, and the optimum temperature was 25 ℃. The PPO activity of A. arguta var. purpurea at growth phase was higher than at dormancy stage. The total phenol content of A. arguta var. purpurea was the minimum in April, May and September.

Key words: Actinidia arguta var. purpurea, polyphenol oxidase activity, total phenol content

摘要： 采用紫果猕猴桃嫩枝和叶柄为试材，分析全年中植株多酚氧化酶（PPO）活性和总酚含量的变化规律。结果表明，紫果猕猴桃植株PPO活性的最适pH为7.0；最佳底物为邻苯二酚，且浓度为0.16 mol/L；最佳温度为25 ℃。紫果猕猴桃植株生长期的PPO活性明显高于休眠期，植株总酚含量在4月、5月、9 月达最低。

关键词: 紫果猕猴桃, 多酚氧化酶活性, 总酚含量