Storage, Transport and Preservation Technology of “+Double Fresh” “1-MCP” for Pineapple
Addtime:2014-09-29 Click:After being harvested, pineapple is still undergoing metabolism and breathes strongly. In addition, bBoth the starch and the content of fructose of fruit decrease gradually, the pulp tissue turns soft and the fruit quality decreases gradually after reaching the best level so that the pineapple will be overdone, decayed and rotten. As the pineapple is mainly matured in high temperature season, it is different difficult to be stored and preserved.
I. Storage Characteristics
There are three varieties of pineapple, Cayenne variety, Queen variety and Spanish variety. Most of the varieties are not easy to be stored and aren’t resistant to low temperature, except Bali of Cayenne variety, Wuming of Spanish variety and the native varieties in Yunnan and Taiwan and etc.;
Pineapple is a non-climacteric fruit, so its storage characteristics are closely related to the harvest maturity, and the higher the harvest maturity, the worse the storability is. However, the pulp of unripe fruit is hard and crispy, but it lacks of the intrinsic gust of fruit. Generally, the nearly 80% matured pineapples are most suitable for storage and long distance transport. The storability of pineapple is also badly affected by storage conditions. Pineapple is susceptible to chilling injury, and it will get injury if the temperature is under the 7℃. The symptoms of fruit being injury are: the color of fruit turns dark, the pulp is hygrophanous and core turns black. The fruit is particularly susceptible to fungal infection to decay when the fruit is removed from the storage. Additionally, under the normal temperature, as the fruit is susceptible to black heart in autumn and winter, it’s not suitable for storage and transportation; while the fruit is easy to rot to beand loss because of the high temperature in summer, so the fruit in spring is the best choice for transporting to the northern regions and storage.
II. Harvest of Pineapple and Notes
As pineapple is a non-climacteric fruit, if it is harvested too soon, the fruit quality will not be good and bad in gust; if it is harvested late, the fruit will be easy to rot. The color of surface is the main gauge to judge the maturity of pineapple fruit. The fruit for storage and transportation should be harvest in the green ripening stage, because the white powder of fruit has been fallen away, the fruit surface has turn yellow green from turquoise, small fruit clearance (fruit suture) turns pale yellow and shiny, the flesh begins to soft, the juice is increasing more, all these show that the level of maturity is 7~8; While for the fresh fruit for sale, it should be harvested in the yellow ripening stage, in this stage, the small fruits at the 2~3 floor from the bottom of the fruit is yellow, the flesh color is orange and full of juicy, high sugar content, fragrance and with the best gust, these show that the level of maturity is 9; And wWhen the color of whole fruit turns deep yellow, the surface of the fruit is in eclipse, the base of flesh is dark yellow, flesh tissue is beginning dehydration, the fruit is in the overripe stage and the fruit had lostmay lose the edible value.
The proper time of harvest is after the morning dew disappeared, and should not harvest in the rainy days in case the fruit rots. Thepineapple is mainly harvested by manpower. When being harvest, people will wear glovesafter choosing the fruit according to the size and the colorIf the fruit will be sold as fresh, crown bud at the top of the fruit can be keptbe careful not to hurt the leaves. While if the fruitsransported and sold for long distance, the crown bud will be removed to save the package and storage cost. After being harvested, the pineapple should be handled with care so as to avoid mechanical damage and sunshine, and should be classified in time and the wounded fruit should be excluded.
III. “1-MCP” Preservation Process
After being dissipated the heat by per-cooling, the pineapple that harvested properly should be fumigated by “1-MCP” preservative timely. This will slow down the mature aging schedule effectively, and delay the process of being soft and rot. The time of preservation can be extended to 2-3 times by storing under low temperature or controlled atmosphere.
IV. Storage Methods
Proper storage conditions of pineapple:
Temperature: 7℃~10℃ Humidity:85%-95%
Gas condition: Oxygen: less than 2%, Nitrogen: more than 98%
(1) Basket storage method. The pineapple that is harvested properly should be per-cooled in the cool shelter and excluded the wounded, and packaged in baskets after being preservative treatment. It should be loaded as 25kg per basket (or plastic turnover box etc.).that the basket should not be overstuffed, in order to avoid crushing or squeezing fruits. The storage temperature should be controlled at 7~10℃, and the relatively humidity should be 85%~90%. The pineapple can be stored more than 20 days by using this method.ventilateduring the storage period, and check and remove the wounded fruits regularly.
(2) Plastic bag storage method. The fruit should be dipped into 500ppm naphthylacetic acid first, and then loaded into plastic bag after drying out by air, padded pieces of rough straw paper in the bag to moisture absorption and avoid injury, tied up the bag, and stored in the cold storage with the temperature of 7~10℃. The fruit can be well stored for more than one month, and the quality shall still be good.
(3) Normal temperature storage. For the pineapple stored by normal temperature, storage period generally short, the fresh quality assurance is within 7~10 days. The store should be with fresh air, intact doors and windows, and the exhaust fan shall be equipped forto ventilation.
V. Storage Management
1. During the storageperiod, the temperature and humidity of the store should be regular checked to keep the temperature and humidity being stable, as the frequently changes of the temperature and humidity may have deadly harm on to pineapples. The humidity should not be too low, in case the wilting or water loss may affect the fruit quality. If the humidity the store is not enough, please water the store . It should be timely defrosting to maintain the constant of temperature. Black heart is the most commonly physiological disease occurring in the storage period, it’s mainly because of the low temperature during the growth, storage and transportation process of the fruit. Please note that the temperature should not below 7℃.
2. Disinfection: It should be timely disinfection during the storage period, disinfection semimonthly will be the best, and the fungicides should be changed frequently so as to get the better effect and the better preservation.
3. Ventilation: During the storage period,ventilate in time to exhaust the bad gas and avoid the occurrence of other physiological diseases. The ventilation should be done every 15 days or so, and half hour around for every time, inplease choose the sunny day with low temperature for ventilation.