Sweet corn ear storage

The production of Sweet Corn ear has strong seasonality, is not resistant to storage, and has a short shelf life, and it is difficult to meet the regular needs of the people. For the preservation and preservation of sweet corn ear, the following aspects should be paid attention to through production practice and scientific research.
1. Harvesting sweet corn of different varieties timely, different climatic conditions and different cultivation techniques, sweet corn ear harvest time is not the same. After taste evaluation and sugar content measurement, generally 18-24 days after the filaments were extracted. Experience has shown that sweet corn ear harvesting is premature, yield is low, sugar content is insufficient, and the aroma is not strong. When harvested too late, most of the sugar in the sweet corn ear is converted into starch, the grain is aged, the epidermis is hardened, and the flavor is not good. Generally, when the Sweet Corn Kernels are full and full, and the skin is broken by hand, the outflow of the white milk is adequate and the harvesting is appropriate.
2. Harvest time and technology The morning and evening are the better times for harvesting sweet corn ear, take the outside temperature lower, so that the heat in the field will be reduced to facilitate faster pre-cooling. At noon high temperatures, should not be harvested.
When harvesting sweet corn ear, it should be removed from the plant together with the loquat leaf. Because there was a significant difference in the rate of decline in the amount of sugar in the loquat leaves and the loquat leaves after harvest. After the ear of the temporal lobe was left for 1 hour, the sugar content began to decrease, and the rate of decline decreased after 4 hours. On the other hand, the sugar content in the leaves of the loquat leaves was relatively stable, with little change at 4 hours after harvest. In the process of picking, the pressure and damage of sweet Corn Kernels in the loquat leaves are prevented. After harvesting sweet corn ears, they should not be piled up under high temperatures for a long time to avoid the sun and rain. They should be shipped back to cold storage and precooled.
3. Pre-cooled sweet corn is a fruit and vegetable with high sensitivity to freezing injury, and is slightly frozen to reduce its quality. The ear of sweet corn returned to the cold storage should be precooled to approximately 0°C as soon as possible. Otherwise, the sugar will be quickly converted into starch. This rate of change is 6 times of 0°C at 10°C and 10 times of 0°C at 21°C. It is 20 times 0°C at 32°C.
The main pre-cooling method used in production is cooling in a cold room. Cold storage temperature 0-5 °C, relative humidity 85%-90%, air flow rate is about 5 meters per second. The pre-cooling process is completed when the center temperature of the sweet corn ear that is put into the cold storage is below 5°C.
Another method is to soak sweet corn ears in cold water at 0°C to cool the ear of corn to about 1°C in a short time. This method is more economical. It is best to add some preservatives in cold water to prevent microbial contamination. There are vacuum gasification cooling methods abroad, but the cost is high.
4. Sweet corn ears in package production are mostly packed in polyethylene film bags or other plastic bags. You can peel the leaves, go to the must, select the panicles after the package; you can also keep all the leaves or leave 2-4 pieces of lotus leaves, and then package, coat the crate, to be sent to the cold storage. The packaging operation is performed at a low temperature (5°C) pre-cooling room.
Chitosan obtained from chitin, because of its good film-forming and biochemical properties, can prevent spoilage without causing hypoxic respiration. Chitosan also has the advantages of being non-toxic, odorless, and easy to decompose, and it will not cause environmental pollution. It has become a better coating material for fresh fruits and vegetables, which can reduce the loss of sweet corn nutrients and extend storage time to some extent. . Low temperature is an important basis for the preservation of sweet corn, and the combination of chitosan coating and low temperature environment is an ideal measure for storage of sweet corn. For sweet corn coated with chitosan, the respiratory intensity and ethylene production were significantly lower than that of non-cleared corn, and the coating effect was better with 1.0% chitosan. After being stored for four days, the antibacterial effect of chitosan is very obvious at the storage temperature of 0°C. The 1.0% chitosan coating can effectively inhibit the growth of bacteria and fungi.
5. Storage Preservation The pre-chilled sweet corn ear is sent to a quick-frozen freezer for quick freezing. The temperature between -25°C and -30°C, and the freezing time is more than 10 hours. When the center temperature reaches -18°C, it can be stored in a low-temperature storage at -18°C for long-term storage. Using this method, the original color, aroma, taste and nutritional value of sweet corn can still be preserved after storage for 7-8 months.
Another method is to store sweet corn ear at a temperature of 0°C. However, 0 °C cold storage method, can not store sweet corn for a longer time, a little longer, it may occur mold mildew phenomenon.

In addition, there is a method of freeze-drying preservation, which involves peeling the leaves of the loquat leaves and water with about 10% of the moisture, packaging them with a polyethylene film, and storing them at room temperature. The ear of sweet corn treated by this method can be stored at room temperature for more than one year, which can perfectly maintain the original flavor and quality of sweet corn. The disadvantage is that the energy consumption of sweet corn ear is larger in this method.