How to Store and Keep Kiwifruit Fresh? A Detailed Guide to Practical Techniques
I. Strengthen field management: Fruit quality is the key to kiwifruit storage and freshness. Strengthen soil management and apply balanced fertilization; scientifically thin flowers and fruits and establish a reasonable leaf-to-fruit ratio; protect natural enemies and strengthen pest and disease control; prune scientifically and do not use hormones such as Daguoling; ensure high quality first, then pursue high yield, ...
I. Strengthen field management:
Fruit quality is the key to kiwifruit storage and freshness. Strengthen soil management and apply balanced fertilization; scientifically thin flowers and fruits and establish a reasonable leaf-to-fruit ratio; protect natural enemies and strengthen pest and disease control; prune scientifically and do not use hormones such as Daguoling; ensure high quality first, then pursue high yield, so as to improve flavor.
II. Scientific harvesting:
1. Harvesting precautions: Do not irrigate the orchard within 5 days before harvest, do not apply nitrogen fertilizer within 20 days, do not harvest within 6 days after rain or when there is morning dew, harvesters must trim their nails and wear gloves, do not drink alcohol before harvest, and do not smoke during harvest.
2. Harvesting techniques and requirements: Harvest at the proper time so that the fruit reaches its due flavor and quality, which is beneficial for storage. (1) Kiwifruit in different parts of the same orchard and different parts of the same plant cannot ripen uniformly, so harvesting should be done in stages and batches, first outside then inside, first upper then lower, and good fruit and undamaged fruit should be harvested according to grade as required; the practice of stripping everything in one pass is opposed. (2) Do not harvest fruit with bruises or pull injuries, deformed fruit caused by pests or poor pollination, or fruit with local sunken and wrinkled areas caused by sunscald. (3) When harvesting, hold the fruit and push it upward, then rotate gently; do not pull hard; handle gently and load and transport carefully to avoid damage and pressure stacking; boxes (baskets) should contain a single variety.
III. Fresh-keeping store management:
1. Disinfection inside the store: (1) Remove odors from the store room and clear out debris. Scrub the floor with saturated potassium permanganate solution or bleaching powder. Fumigate with 5-15 grams of sulfur per cubic meter mixed with dry sawdust, keep the store door tightly closed for 24 hours, and start the machine to cool down after 48 hours.
2. Pre-cooling and bagging: Lower the temperature of the disinfected store room or pre-cooling room to 0°C 2 days in advance. (2) Put the harvested fruit into the store for pre-cooling within 24 hours (the daily pre-cooling amount put into the store is about 15% of the cold store capacity), keep the store temperature stable at about 3°C, and after all the fruit has been put in and pre-cooling is completed, grade and box it as required. (3) When bagging, use airtight fresh-keeping bags, open the bottom of the bag, lay it flat inside the box, place the fruit gently into the bag layer by layer to prevent damage to the fruit top or piercing of other fruit, and add the special fresh-keeping agent. (4) Stack the fruit boxes with tied bags by grade; at present, the relatively ideal stacking method is plum-blossom stacking.
3. Storage: For kiwifruit storage, the "four degrees" must be well controlled. (1) Temperature. Temperature is the most critical factor determining whether kiwifruit can be stored ideally; constant low temperature is one of the most effective means of reducing kiwifruit respiration and slowing saccharification and softening. For different varieties and climatic conditions, and different cultivation techniques and storage stages, the storage temperature for kiwifruit differs. Storage temperature must not only be suitably low, but also stable by stage; a storage temperature that suddenly turns cold within a certain period is very unfavorable for kiwifruit storage and freshness. A storage temperature close to freezing point in each stage is most favorable for storage and freshness, generally about 0°C, but a sudden change in store temperature that does not go below freezing point may also cause chilling injury to kiwifruit and affect storage quality. (2) Gas concentration. Kiwifruit is a climacteric berry; during storage it absorbs oxygen and produces carbon dioxide and ethylene. Reducing oxygen concentration, increasing carbon dioxide concentration, and removing ethylene gas are important means of kiwifruit storage and freshness. Ventilation and air exchange in the store is an effective way to improve the gas environment in the store room and can remove harmful gases from the environment. (3) Humidity: If humidity is too low, kiwifruit may lose water, the peel may wrinkle, and it becomes prone to infection and spread. It should generally be controlled at 96-95%. (4) Cleanliness: There must be not only cleanliness of the fruit but also cleanliness of the environment. The fruit must be free of pests and contamination; during storage, fruit infected by pathogens or rotten and deteriorated must be handled promptly; the store room must be cleaned of debris in a timely manner and harmful gases discharged.
Temperature, gas concentration, humidity, and cleanliness are mutually connected and mutually affecting.
4. Standardize fresh-keeping store management: Unauthorized personnel must not enter; do not enter the store after drinking alcohol or carrying aromatic substances; smoking and open flames are strictly prohibited; mixing with fruits and vegetables that release aromatic odors is strictly prohibited; ensure the cold store is insulated and sealed, and check the store temperature regularly; strengthen regular inspection, repair, and maintenance of machinery and equipment to prevent automatic control failure or cooling loss of control.