Internal ethylene concentration (IEC) and activities of peroxidase (POX), polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL) were analyzed to evaluate their effects on browning in late-harvested ‘Empire’ apples (Malus × domestica Borkh.), during air storage at 0.5 °C for five months, and for ‘Fuji’ apples treated with 1-methylcyclopropene (1-MCP), stored for seven months. IEC remained higher in the ‘Empire’ apples compared to values observed in the ‘Fuji’ apples for up to three months in storage, although 1-MCP treatment reduced the IEC in both fruit cultivars. Antioxidant enzymes, such as PPO, POX, and PAL, mostly increased in the flesh and core tissues in both 1-MCP-treated apple cultivars, but were slightly higher in the ‘Empire’ apples between one and three months of storage time. Browning developed in the ‘Empire’ apples after three months of storage, with high susceptibility to incidences of browning observed on the 1-MCP-treated fruit.

中文翻译：

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抗氧化剂活性对“帝国”和“富士”苹果褐变的影响

分析了内部乙烯浓度（IEC）以及过氧化物酶（POX），多酚氧化酶（PPO）和苯丙氨酸氨裂解酶（PAL）的活性，以评估它们对收割后的“帝国”苹果（海棠×家蝇）褐变的影响（Borkh。），在0.5°C的空气中存储五个月，对于使用1-甲基环丙烯（1-MCP）处理的'富士'苹果，则存储七个月。与“富士”苹果在储存三个月中观察到的值相比，“帝国”苹果中的IEC仍然更高，尽管1-MCP处理降低了两种水果品种的IEC。在两种经过1-MCP处理的苹果品种中，PPO，POX和PAL等抗氧化酶大多在果肉和核心组织中增加，但在储存1至3个月的“ Empire”苹果中则略高。储存三个月后，'Empire'苹果中出现了褐变，对1-MCP处理过的水果有很高的褐变发生率。