Controlled atmosphere storage and fresh keeping of

Controlled atmosphere storage and preservation of fragrant pears

fragrant pears are the abbreviation of Korla fragrant pears, which are famous and specialty fruits in Xinjiang. In recent years, the planting area of fragrant pear has been expanding, the output has increased significantly, and the market demand is also growing. Therefore, it is imperative to solve the problem of storage and preservation of fragrant pear. After more than two years of research and experiments, we have summarized a complete set of storage and fresh-keeping technology of fragrant pears, which is now introduced as follows:

1. Pre harvest preparation

fragrant pears should be sprayed with 0.3% calcium chloride or calcium nitrate solution three times before harvest, which can improve the storage resistance of fragrant pears and reduce fruit browning. Watering should be stopped about 20 days (days) before harvest to avoid intolerant storage and help them better solve the market demand for "watering pears"

2. Harvest in time

fragrant pears are generally harvested from late August to late September, when the fruit surface is smooth, with longitudinal grooves and thick wax, and the peel is cyan and yellow, with a slight blush on the sunny side. The browning rate of fruits harvested too early and too late was higher than that of fruits harvested normally. Harvesting later is beneficial to improve the Storability of fragrant pear and prevent physiological diseases. The fruit of fragrant pear is harvested manually. It should be picked, handled and placed gently to avoid fruit browning caused by human damage. After picking, put each fragrant pear bag into a wooden box, which should not be too full. Each box should be 60 ~ 80kg. After packing, it should be transported back to the cold storage immediately

3. Storage management

① warehousing in time. Fragrant pears are respiratory climacteric fruits, and the yellowing of the peel is the sign of the arrival of respiratory peak. Therefore, they should be stored 48 ~ 72h (hours) after harvest and cooled rapidly. According to the warehousing quantity, warehousing and refrigeration shall be carried out in batches. After all warehousing, the temperature shall be reduced to about 0 ℃ 3 days after closing the door

② pay attention to stacking. When entering the warehouse, attention should be paid to the height and method of stacking wooden cases. The sizes of wooden cases used are 100cm long, 60cm wide and 50cm high. Every five wooden cases are placed horizontally into one stack, with an interval of 10cm to facilitate gas circulation. The maximum stack is 12 layers (6m), which is generally stacked in a ladder shape from the warehouse door, so as to facilitate sampling inspection during storage. In addition, the direction of the ventilation duct should be parallel to the direction of the air duct or the wind direction of the air duct, so as to facilitate heat dissipation and discharge of CO2 and other harmful gases

③ temperature regulation. The suitable storage temperature of fragrant pears is -1 ℃ ~ 0 ℃, which is lower than that of Yali pear, crisp pear, apple pear, etc. This is because fragrant pears are low-temperature resistant. Jinan testing machine factory has strong temperature capacity in 2017. Even if there is slight freezing injury, they can recover slowly, and the color, aroma and taste change little. If the storage temperature of fragrant pear is too high, the fruit respiration will speed up, and the storage period will be shortened; The storage temperature is too low, which is easy to produce chilling injury, and the functional enzymes in the fruit are destroyed, which makes the fruit browning and shortens the storage period. Therefore, high or low storage temperature will reduce the good fruit rate and quality of fragrant pear

④ gas composition. The best gas composition for controlled atmosphere storage of fragrant pear is: o24% - 6%, CO22% - 4%. Because fragrant pear fruit is very sensitive to high CO2 in storage environment, high CO2 is often an important cause of Tissue Browning

⑤ humidity control. The humidity of the storage environment is the key factor for the controlled atmosphere storage of fragrant pears. Controlled atmosphere storage of fragrant pears requires a relative humidity of 90% to 95% of PVC pipes with a diameter of 1.5m. If the humidity is too high, it is easy to produce mold spots in the wooden box. If these mold spots stick to the peel of fragrant pear, they are easy to form black spots and affect the appearance of the fruit; Insufficient humidity, serious water loss of fruit and yellowing of peel directly affect the quality of fragrant pear. In addition, it is best to use a combination of air humidification and ground humidification. The ground water level is generally 2 ~ 3cm. If the water level is too high, the wooden box is easy to mold, and the humidity is too low to meet the requirements. Humidifier with good atomization, not easy to freeze, convenient operation and low price should be selected for humidification in the air, and fragrant pears at the humidification port should be covered with plastic film to avoid chemical rust due to excessive humidity

4. Fruit ripening

after 240 days of storage at -1 ℃ ~ 0 ℃, o24% ～ 6%, CO2 2% ～ 4% and relative humidity of 90% ～ 95%, the good fruit rate of fragrant pears collected in time can reach 95% ～ 98%. Fragrant pears can be directly listed on the scrap market on the 3rd day without ripening after delivery, and their color, aroma and taste are close to those of naturally ripened fragrant pears after picking

Chen guogang

source of information: farmer wealth Consultant