When the activity of polyphenol oxidase reaches the maximum, watermelon arrives at peak of breath.The active dynamic changes of polyphenol oxidase can indicate the arrival of the high breath peak.

• 研究表明：多酚氧化酶活性达到最大值，紧接着到达呼吸高峰，说明多酚氧化酶的活性变化可以预示呼吸高峰的来临；