Abstract: In order to study the effects of three circulation modes of room temperature, cold chain and broken-off cold chain on the quality of peach fruit, the fruit were stored under temperature conditions simulating each circulation mode. Changes in flesh firmness, the contents of cell wall pectin, soluble sugars and titratable acids, and sugar and organic acid composition were analyzed during the simulated circulation process. The results showed that the fruit quality was significantly affected by the circulation temperature. The commodity value was lost within four days in the simulated room temperature environment. The constant low temperature condition (simulated cold chain circulation) could well maintain the fruit quality during storage and shelf life. However, the quality of peach fruit in the simulated broken-off chain circulation condition rapidly decreased after entering the shelf life period due to the increase in temperature at various stages such as packaging and warehouse-in/warehouse-out during storage. The flesh firmness (2.14 g/cm2), sucrose content (46.48 mg/g) and malic acid content (3.13 mg/g) were significantly lower than those in the simulated cold chain circulation group on the 2nd day of shelf life (P < 0.05). The fluctuation of circulation temperature caused by broken-off cold chain during the transportation and storage of peaches should be avoided as much as possible. These results will be helpful for the improvement of the cold chain circulation systems for vegetables and fruits.

Key words: peach fruit; simulated circulation modes; temperature; firmness; sugars and acids