The activity of PPO in juice decreased step by step with the increasing of heating temperature and pressureholdingtime.
随着保压时间延长和温度升高，梨汁中PPO相对活性逐渐降低。
2
The activity of PPO in the juice decreased gradually with the rise of heating temperature and the extension of pressureholdingtime.
随着保压时间的延长和温度的升高，桃汁中多酚氧化酶相对活性逐渐降低。
3
The raw materials, extrusion pressure, pressureholdingtime and molding temperature during extrusion moulding have great effects on the quality of products.