**3. Influence of precooling process**

As living organizations, the fruit and vegetable are affected by severe environmental changes in precooling process. During the precooling process, there are physiological changes in the inside of the fruit and vegetable to adapt to the environment, which can be reflected from two aspects. One is the change of physical structure, such as the body stress, epidermal pore and so on; another one is biochemistry changes in vivo like respiratory intensity and nutrition. In order to investigate the effect of the precooling process, the preceooling experiments of three kinds of fruits were carried out, and the results were compared with the traditional one.

#### **3.1 Material preparation and test method**

In this experiment, the experimental storage of different precooling processes on three fruits was carried out, including kiwi, pear and peach.
