How to Store Fresh Peaches to Extend the Supply Period

Peaches have many varieties, and with early, mid and late maturing types and different growing methods, they are supplied to market successively from April to October. Fresh peaches have a short storage life and are prone to rotting and spoilage. If suitable fresh-keeping methods are adopted, the supply period of fresh peaches can be extended and economic returns improved.

Harvest without injury, grade and pack. To judge peach fruit maturity: first, after the fruit has fully developed, the skin begins to lose its green color, the flesh is slightly firm, and colored varieties have basically reached full color, this is the firm-ripe stage. Second, when the fruit's ground color is light green and the fuzz on the fruit surface begins to color, it is at the seven-to-eight-tenths ripe stage. Fruits at the firm-ripe stage and the seven-to-eight-tenths ripe stage are relatively tolerant of storage and long-distance transport. Because peach maturity is uneven, most varieties need 2 to 3 harvests. During harvest, strictly prevent bruising and puncturing; pick the fruit with the stem attached, preferably harvesting at low temperature in the morning, and process immediately after picking. Remove leftover, damaged, inferior, malformed and dirty fruits, grade them by size and pack them separately. Commonly used containers hold 5 kg to 10 kg, lined with paper or polyethylene foam paper; for premium fruit, use foam net sleeves for individual fruits. During handling, remember to handle gently, load and unload gently, and prevent bruising.

Fresh-keeping treatment to prevent rot diseases. During storage, peaches are prone to brown rot, soft rot and blue-green mold. The sec-butylamine series of preservative and fresh-keeping agents can be used to kill penicillium and green mold. Commonly used are carbendazim at 15 times dilution (fruit washing), and a mixture of benlate at 100 mg/kg to 200 mg/kg and dichloroaniline (DCNA) at 450 mg/kg to 900 mg/kg (fruit dipping). When washing or dipping fruit with the above agents, use clean water to prepare the solution, and after dipping, wait for the water on the fruit surface to evaporate before packing.

Choose a good environment and control temperature for storage. The suitable temperature for storing peach fruit is 0°C to 3°C; for mid and early maturing varieties the temperature is slightly higher, for example white flower and red flower honey peaches are stored at 1°C to 3°C, while winter snow honey peaches, Chinese longevity peaches and winter peaches are refrigerated at 0.5°C to 1°C. Because peach fruit is relatively sensitive to low temperature, long storage at 0°C can easily cause chilling injury. To prevent or reduce the occurrence of chilling injury, facilities with high temperature-control precision must be used, or the intermittent warming refrigeration method can be adopted, that is, the fruit is first stored at 0°C for 1 to 4 weeks, then warmed to 18°C to 20°C for two days, then cooled again to 0°C for storage. Choose a wall-mounted automatic cold storage room with temperature-control precision of storage at 0°C. The cooling speed is fast, the storage temperature precision is 0.1°C, the cooling speed is fast, the storage temperature is uniform, and cooling and warming can be automatically adjusted as needed, which can effectively reduce or avoid the occurrence of chilling injury.

When storing peaches, the suitable oxygen concentration is 1% to 3% and the carbon dioxide concentration is 4% to 5%. When storing peaches in physiological small packaging bags, the carbon dioxide concentration should be below 8% and the oxygen 5% to 14%. After storage begins, check regularly: for short-term stored peach fruit, observe once every day; for medium- and long-term fruit, check once every 3 to 5 days.