Effects of Different Cooling Methods on Postharvest Physiology of Yali Pears during Ice Temperature Storage

The effects of slow and rapid cooling methods on the postharvest physiology of Yali pears during ice temperature (-0.5 degrees C) storage were investigated. Respiration rate, ethylene production, browning index and polyphenol oxidase(PPO) activity were used to evaluate the quality of Yali pears. The results showed that the slow cooling treatment decreased the levels of respiration rate, ethylene production, and PPO activity of Yali pears, and delayed the occurrence of the respiration, ethylene, and PPO activity peak compared to the rapid cooling treatment. The browning indexes of Yali pears with slow cooling treatment were lower than that of rapid cooling treatment. The results indicate that the cooling method may be an important factor affecting the storage quality of Yali pears. The slow cooling can delay the occurrence of physiological disorder during ice temperature storage.