【摘要】 为确定酶促褐变的程度 ,对冷藏期间 3种褐变敏感度不同的梨果皮中的酚类物质含量、多酚氧化酶 (PPO)活性及褐变度进行了比较。在 0℃下 6个月的冷藏期间 ,苹果梨、鸭梨和冬果梨果皮中的总酚和绿原酸含量以及褐变度呈下降趋势。贮藏 1个月的苹果梨和鸭梨以及贮藏 2个月的冬果梨多酚氧化酶 (PPO)活性最高。之后便逐步降低。品种内比较发现 ,褐变度与总酚和绿原酸含量之间呈良好正相关 ,但与PPO活性之间的相关度较低。供试品种中 ,以苹果梨总酚含量、PPO活性及褐变度最高 ,由此表明 ,该品种果皮对褐变更敏感。更多还原

【Abstract】 To determine the degree of enzymatic browning, the phenolic concentrations, polyphenoloxidase(PPO) activity and degree of browning were compared for the peel of three cultivars with different susceptibility to browning at cool storage. During 6 months at 0℃, total phenolics, chlorogenic acid and degree of browning Pingguo, Duck and Dongguo pears decreased. There was an increase in PPO activity in Pingguo and Duck pears at 1 month, and 2 months of storage in Dongguo pear, after which it declined at the end of the period investigated. A better correlation between degree of browning and total phenolics or chlorogenic acid was established. However, a relatively low correlation was observed between degree of browning and PPO activity when comparing each cultivars. Among the cultivars studied, Pingguo pear had the highest level of total phenolics, PPO activity and degree of browning. The results indicated that the cultivar was more susceptible to browning in peel.更多还原