1. Quick freezing method
1. Harvest at the right time. Generally, spring-sown varieties should be harvested 23-28 days after silking, while autumn-sown varieties often take about 30 days. Cobs should be worn during harvesting to reduce contamination and mechanical damage to corn cobs during harvesting and transportation. At the same time, it can delay the catabolism of the ear kernels and help maintain the freshness of the ear.
2． preprocessing. After harvesting, corn cobs must be spread out in a ventilated and cool place to prevent accumulation and heat generation. Then the bracts are manually removed, the corn silk is removed, and the ears that are insect-eaten, missing kernels, too old, or too tender are removed. Soak the arranged ears in 2% salt water for 30 minutes, rinse them in clean water for 8-10 minutes, then remove them and drain them.
3． Boil and blanched. The time for boiling and blanching is 25-30 minutes, and the temperature is above 90°C. When blanching, all ears should be immersed in water to ensure even blanching.
4． Cool and drain. The blanched fruit ears should be cooled immediately and rinsed with cold water at 5°C for about 10 minutes, so that the temperature of the fruit ears quickly drops below 10°C.
5. Pack and freeze. Put the cooled fruit ears into a composite film bag and seal it with a sealing machine. Freeze in the freezer at -35°C for 8-10 hours.
6. Cold storage. After quick freezing, the ears are packed into boxes and stored in -18°C cold storage.
2. Salting method
1. Material selection and finishing. Select corn cobs from the fresh ears of waxy corn in the milk-ripening stage that are insect-free, disease-free, uniform in size, and full of seeds. Remove the bract leaves and ear filaments, and rinse them with clean water.
2． Pre-cooked. Put the fresh ears into hot water of 85-95℃, blanch them for 2-3 minutes, then take them out and put them in flowing water to cool to 20-25℃.
3． Salted. Dry the cooled fresh ears slightly and immerse them in a salt solution for storage. The preparation method of the salt solution is as follows: dissolve table salt in water to prepare a solution with a concentration of 20%, boil it, and filter and clarify it. Before salting, add corn preservative at a ratio of 3% to 5% of the treated ears (1 kilogram of preservative can treat 6,000-8,000 ears), and the salting effect will be better.
4． Turn over the cylinder. After salting for 35-40 days, the corn ears in the tank should be turned over once. If the container has been sealed, just tip the container on the floor and roll it a few times.
5. Change the water. The water needs to be changed about 20 days after turning over the tank. Remove the fruit ears and put them into 10% salt solution. When the temperature gradually decreases, the amount of preservative can be reduced to 1%.
6. rinsing. 10 days before going on the market, rinse the fruit ears in clean water to remove the salt smell.
3. Bag storage method
1. Corn ear finishing. Remove corn ears that are moldy, rotten, insect-eaten, damaged, deformed, old, or too tender. Peel off the corn bracts and whiskers, rinse them with clean water, grade them according to the size and length of the ears, and transfer them to baskets for later use.
2． Precook, cool, and dry. Add an appropriate amount of citric acid and salt to the pre-cooked hot water and pre-cook for 5 minutes to bring the corn cob temperature to over 95%. When pre-cooking, gently turn the corn cobs to heat them evenly. Quickly cool the pre-cooked ears to 50-60°C with running water, and then soak them in a corn preservation solution containing 3%-5% for 3-5 minutes. minutes, take it out to dry and set aside.
3． Bagging and sealing. Before bagging, dry the water droplets on the fruit ears with clean gauze, then put them into vacuum bags and seal them with a vacuum sealing machine.
4． Sterilize. Put the sealed packaging bag into loo°C boiling water for sterilization for 20 minutes, take it out, cool it with cold water, remove the bulging bags and other unqualified products, and pack them into the warehouse.