Low-temperature preservation process for sweet-waxy corn in refrigeration house

Abstract

The invention provides a low-temperature fresh-keeping process for sweet-waxy corn in a refrigeration house, and relates to the technical field of sweet-waxy corn fresh-keeping, and the low-temperature fresh-keeping process comprises the following steps: step 1, screening and pretreating raw materials; step 2, pre-cooling treatment; step 3, packaging treatment; step 4, quick-freezing treatment; step 5, low-temperature storage; step 6, unfreezing treatment; the method comprises the following specific steps: 1, screening and pretreating raw materials, namely selecting full sweet-waxy corn without diseases and insect pests, retaining complete bracts, removing impurities and damaged parts, cleaning with clear water, performing primary sterilization, and then cleaning and draining water after sterilization; the method has the advantages that preservation with husks can provide a natural physical barrier for corn and reduce external microbial contamination, moisture and nutrient substances in bracts can be slowly supplemented to corn kernels to a certain extent, freshness of the corn kernels is maintained, and soaking with the sodium bicarbonate solution not only sterilizes, but also can adjust the pH value of the surface of the corn and inhibit growth of harmful microorganisms, so that the corn kernels are healthy and healthy. And favorable conditions are created for fresh keeping.

Description

Technical Field

[0001] The present invention relates to the technical field of sweet waxy corn preservation, and particularly relates to a low-temperature preservation process for sweet waxy corn in a cold storage. Background Art

[0002] Sweet waxy corn is rich in various nutrients and is deeply loved by consumers. However, due to its active post-harvest physiological metabolism and the easy conversion of sugar into starch, the quality deteriorates. Traditional preservation methods are difficult to effectively maintain the quality of sweet waxy corn under frozen conditions. In particular, for sweet waxy corn with husks, problems such as poor taste, generation of strange smells, and difficulty in passing food inspections often occur after thawing. Summary of the Invention

[0003] The purpose of the present invention is to solve the deficiencies existing in the prior art, and a low-temperature preservation process for sweet waxy corn in a cold storage is proposed. The technical solution adopted by the present invention is as follows:

[0004] A low-temperature preservation process for sweet waxy corn in a cold storage includes the following steps: Step 1, raw material screening and pretreatment; Step 2, precooling treatment; Step 3, packaging treatment; Step 4, quick-freezing treatment; Step 5, low-temperature storage; Step 6, thawing treatment.

[0005] As an improvement, the specific steps of Step 1, raw material screening and pretreatment are as follows: Select sweet waxy corn without pests and diseases and with plump grains, retain the complete husks, remove impurities and damaged parts, wash with clean water, then conduct preliminary sterilization, and after sterilization, wash and drain the water.

[0006] As an improvement, the specific steps of Step 2, precooling treatment are as follows: Quickly transfer the pretreated sweet waxy corn to a precooling room, and use the forced cold air precooling method to reduce the overall temperature of the corn to the required low temperature state.

[0007] As an improvement, the specific steps of Step 3, packaging treatment are as follows: Select a composite fresh-keeping bag to conduct vacuum packaging on the sweet waxy corn with husks.

[0008] As an improvement, the specific steps of Step 4, quick-freezing treatment are as follows: Put the packaged sweet waxy corn into a quick-freezing storage to quickly cool it to below minus 18 degrees Celsius.

[0009] As an improvement, the specific steps of Step 5, low-temperature storage are as follows: After quick-freezing is completed, transfer the corn to an environment of minus 10 degrees Celsius for long-term storage.

[0010] As an improvement, the specific steps of Step 6, thawing treatment are as follows: Take out the sweet waxy corn and place it in warm water or at room temperature for thawing.

[0011] The beneficial effects of the present invention are as follows:

[0012] A low-temperature fresh-keeping process for sweet glutinous corn in a cold storage. Keeping the corn with its husk can provide a natural physical barrier for the corn, reducing external microbial contamination. At the same time, the moisture and nutrients in the husk can slowly supplement the corn kernels to a certain extent, maintaining their freshness.

[0013] Soaking in sodium bicarbonate solution not only sterilizes but also adjusts the surface pH value of the corn, inhibiting the growth of harmful microorganisms and creating favorable conditions for fresh-keeping.

[0014] Combining quick-freezing and specific low-temperature storage conditions can not only maintain the quality of the corn but also achieve long-term fresh-keeping under relatively energy-saving conditions. Specific implementation manners

[0015] To make the content of the present invention easier to be clearly understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below.

[0016] Step 1. Raw material screening and pretreatment: Select sweet glutinous corn that is within 24 hours after picking, free of pests and diseases, and has plump kernels. Keep the complete husk, remove impurities and damaged parts, rinse it clean with water, drain the surface water, soak the corn in sodium bicarbonate solution for preliminary sterilization and adjusting the surface microenvironment of the corn, and then fish it out and drain the water again.

[0017] Step 2. Pre-cooling treatment: Quickly transfer the pretreated sweet glutinous corn to a pre-cooling room, and adopt the forced cold air pre-cooling method. Under the environment of 0 - 5°C, quickly and evenly reduce the overall temperature of the corn to about 5°C to reduce the respiratory metabolism rate of the corn.

[0018] Step 3. Packaging treatment: Select a polyethylene-vinyl alcohol copolymer composite fresh-keeping bag with high barrier performance, individually pack the pre-cooled sweet glutinous corn with its husk into the fresh-keeping bag, evacuate the air, and heat-seal the bag mouth to reduce the entry of oxygen and moisture, inhibiting the growth of microorganisms and oxidation reaction.

[0019] Step 4. Quick-freezing treatment: Put the packaged sweet glutinous corn into a quick-freezing storage, and carry out quick-freezing at a low temperature of -40°C to quickly reduce the central temperature of the corn to below -18°C, quickly pass through the ice crystal formation zone, and reduce the damage of ice crystals to the cell structure of the corn.

[0020] Step 5. Low-temperature storage: After quick-freezing, transfer the corn to a cold storage with a temperature of -10°C ± 1°C and a relative humidity of 85 - 90% for long-term storage. Under this environment, the respiratory metabolism and the quality deterioration rate of the corn are effectively controlled.

[0021] Step 6. Thawing treatment: When it is needed to be eaten, take out the frozen sweet glutinous corn with husk from the cold storage and place it indoors for natural thawing or thaw it in warm water. During the thawing process, the ice crystals inside the corn slowly melt, which can better maintain the cell structure and moisture, and reduce the loss of juice.

[0022] Preserving with husk can provide a natural physical barrier for the corn, reduce external microbial contamination. At the same time, the moisture and nutrients in the husk can slowly supplement the corn kernels to a certain extent, maintaining their freshness.

[0023] Soaking in sodium bicarbonate solution not only sterilizes but also can adjust the surface pH value of the corn, inhibit the growth of harmful microorganisms, and create favorable conditions for preservation.

[0024] Pre-cooling treatment rapidly reduces the temperature of the corn, effectively slows down the respiration, and reduces the consumption of nutrients and flavor loss.

[0025] The high barrier performance of the EVOH composite fresh-keeping bag greatly reduces the penetration of oxygen and moisture, and significantly extends the fresh-keeping period of the sweet glutinous corn.

[0026] Combining quick-freezing and specific low-temperature storage conditions can not only maintain the quality of the corn but also achieve long-term preservation in a relatively energy-saving way.

[0027] After thawing, the sweet glutinous corn with husk processed according to this process has a sweet, glutinous and soft taste and a strong flavor.

[0028] The above are only the preferred embodiments of this invention patent and are not used to limit this invention patent. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of this invention patent shall be included within the protection scope of this invention patent.

Claims

1. A low-temperature preservation process for sweet and sticky corn in a cold storage, characterized in that: The following steps are involved: Step 1: raw material screening and pretreatment; Step 2: precooling; Step 3: packaging; Step 4: quick freezing; Step 5: low temperature storage; Step 6: thawing.

2. A sweet and sticky corn cold storage low temperature preservation process according to claim 1, characterized in that: The specific steps of step 1, raw material screening and pretreatment are: select sweet and sticky corn without pests and diseases and with full grains, keep the bracts intact, remove impurities and damaged parts, wash with clean water, and then perform preliminary sterilization, and then wash and drain the water after sterilization.

3. A cold storage low temperature preservation process for sweet and sticky corn according to claim 1, characterized in that: The specific steps of the step 2, pre-cooling treatment are: quickly transferring the pre-treated sweet and sticky corn to the pre-cooling room, and using forced cold air pre-cooling to reduce the overall temperature of the corn to the required low temperature state.

4. A cold storage low temperature preservation process for sweet and sticky corn according to claim 1, characterized in that: The specific steps of step 3, packaging processing are: using a composite fresh-keeping bag to vacuum-pack the sweet and glutinous corn with skin.

5. A cold storage low temperature preservation process for sweet and sticky corn according to claim 1, characterized in that: The specific steps of the step 4, quick freezing treatment are: putting the packaged sweet and sticky corn into a quick freezing warehouse and quickly cooling it to below minus 18 degrees.

6. A cold storage low-temperature preservation process for sweet and sticky corn according to claim 1, characterized in that: The specific steps of step 5, low-temperature storage are: after quick freezing, the corn is transferred to an environment of minus ten degrees for long-term storage.

7. The low-temperature preservation process of sweet and sticky corn in cold storage according to claim 1, characterized in that: The specific steps of the step six, thawing treatment are: taking out the sweet and sticky corn and placing it in warm water or room temperature for thawing.