How long can young garlic shoots be refrigerated? How much data do you need about horizontal temperature and humidity? If there are professionals.

There are three storage methods for young garlic shoots: one is ice storage; The second is the general refrigeration method; The third is the air conditioning cooling method.

(1) Ice room storage method is suitable for small-scale storage of garlic bolts by farmers in areas with abundant ice sources in Northeast China. However, this method consumes a lot of ice and labor, has a small scale, poor preservation effect, high loss and high cost, and it is difficult to form mass production.

(2) The general cold storage method, that is, stacking baskets in the cold storage, is relatively simple and easy. The storage temperature is kept at 0℃ 0.5℃, and the relative humidity (RH) of air is kept above 90%. However, the storage period is short, usually about 3 months, and the preservation effect is not ideal. The young garlic shoots age quickly after leaving the warehouse and are unpalatable.

(3) The air-conditioned cooling method can be divided into conventional air-conditioned cooling method and limited air cooling method due to the different strictness of gas regulation. The former requires high equipment and technology and has not been widely used in China at present; The latter was developed on the basis of the modified atmosphere storage method successfully researched by Shenyang Vegetable Company in 1970s, and it was widely used in China, forming industrialization. According to the different storage methods of garlic shoots, the gas-limited refrigeration method can be divided into two types: bag shelf refrigeration method and big tent sealed refrigeration method, of which the former is widely used. According to the different packaging bags, the methods of bagging money can be divided into three types: ordinary plastic bag shelf refrigeration method, silicon window bag shelf refrigeration method and fresh-keeping bag shelf refrigeration method. The first method has a large amount of bags, and the plastic bag is green, which has a camouflage effect, that is, when the garlic shoots are sold out of the warehouse (especially under the irradiation of high-pressure mercury lamp at night), the green garlic shoots are more truly attracted by the bag color, even if the garlic shoots turn green. However, in the process of storage, it is necessary to open the bag frequently to deflate, and to wipe off the airflow water on the inner wall of the plastic bag with a towel to prevent corruption and deterioration, so the management cost is labor-intensive, the cost is high, and the preservation effect is not ideal (often compensated by bag color). The second method can reduce the trouble of "wiping sweat" during the storage of garlic shoots, but due to the small opening of the silicon window, natural ventilation cannot be completely realized, and manual bag opening is still needed for ventilation, but the interval is longer than that of the first method; Silicone rubber film is more expensive, which increases the cost; During the whole storage period, co2 permeates through the silicone rubber membrane faster than o2, although co2 poisoning is not easy to occur, o2 has high humidity, and the top of garlic bolt often mildew during storage. In the third method, because the fresh-keeping bag has good overall air permeability, it is generally unnecessary to open the bag for ventilation and "sweat wiping" during the storage of garlic shoots, which greatly reduces the management labor intensity and employment, and reduces the cost. However, the bagging capacity quota is 15kg, which increases the consumption of fresh-keeping bags and the bagging cost per garlic bolt. Although the preservation effect is better than the first one, it lacks the "icing on the cake" of bag color.

Simple Modified Atmosphere Refrigeration Technology for Garlic Bolts

Standard Category: Agricultural Fruit and Vegetable Standards Implementation Date: Click: 474

1 range

This standard specifies the technical conditions and operation methods required for simple modified atmosphere refrigeration of garlic shoots.

This standard is applicable to simple modified atmosphere refrigeration of garlic shoots.

2 reference standard

The clauses contained in the following standards constitute the clauses of this standard by reference in this standard. At the time of publication of this standard, all versions shown are valid. All standards will be revised, and all parties using this standard should explore the possibility of using the latest version of the following standards.

SB/T 10330—2000 garlic bolt

3 definition

This standard adopts the following definitions.

Simple Modified Atmosphere Refrigeration Technology for Garlic Bolts

simplecontrolledatmosphorescoldstoragetechniqueofgarlicbolt

A modified atmosphere storage method. On the basis of cold storage, garlic shoots are sealed in plastic film bags or plastic tents, and the oxygen content is reduced and the carbon dioxide concentration is increased through the respiration of garlic shoots, and then the air is released for storage according to the indexes of carbon dioxide and oxygen.

4 Harvest and quality requirements

4. 1 recovery requirements

Choose raw materials without pests and diseases, and harvest them in sunny days. Don't cut with a knife when harvesting. After harvesting, it should be placed in a packaging container that is not easy to be damaged and conducive to ventilation, avoiding rain and exposure, and quickly transported to the precooling place.

4.2 Quality requirements

According to the relevant provisions of SB/T 10330.

5 preparation before refrigeration

5. 1 sterilization

The cold storage is fumigated with sulfur at the dosage of (10- 15)g/m3 or sprayed with (1-2)% formaldehyde (formalin). During fumigation and disinfection, various containers, shelves, etc. Can be put into the warehouse together, sealed for (24-48)h, and then ventilated to discharge all the residual drugs.

5.2 Selection and precooling

5.2. 1 Garlic bolts from different producing areas, batches and grades should be packed in a pre-cooling room or a cool and ventilated place for heat dissipation (ventilation pre-cooling is adopted to make the temperature drop rapidly). At the same time, sort according to 4.2.

5.2.2 Align the garlic shoots that meet the quality requirements, and bind them with plastic ropes (belts) outside the stems of garlic shoots (3-5 cm), with each bundle weighing (0.5- 1.0) kg. If a plastic tent is used for controlled atmosphere refrigeration, it should

5.2.3 The sorted garlic bolts are weighed, put on shelves and precooled on the same day.

5.2.4 When the product temperature drops to 0, turn off the fan of the evaporator in the warehouse and ignite the prepackaged thiabendazole smoke agent in the warehouse from the inside out. Open the refrigerator after sealing for 4 hours. See Appendix D (standard appendix) for the usage of thiabendazole.

5.2.5 When the crystallization temperature of garlic bolt is stable at 0, it can be bagged or covered for refrigeration.

6 cold storage method

6. 1 plastic film bag modified atmosphere refrigeration

See Appendix A (standard appendix) for packaging materials and specifications.

6. 1.2 random sampling method was adopted, and representative bags were set up according to different producing areas, batches and grades for inspection and determination. The number of each origin, each batch and each grade shall not be less than 3 repetitions.

6. 1.3 Open the bag and take a breath according to the gas index, and take a breath for (3-5)h each time (short in the early stage and long in the late stage). After the gas in the bag is fully exchanged with the atmosphere, the concentration of residual carbon dioxide in the bag shall not be higher than 65438 0%.

6.2 Plastic film tent modified atmosphere refrigeration

6.2. 1 Put the bundled garlic sprouts and garlic buds on the cold shelf evenly and precool. The stacking thickness of each layer is (30-35) cm. When the product temperature is stable at 0℃, carry out thiabendazole anticorrosion treatment according to 5.2.4. See Appendix A (standard appendix) for the production and specifications of plastic film account.

6.2.2 After the tent is covered, the young garlic shoots shall not contact with the plastic film. After the account is closed, the contents of oxygen and carbon dioxide gas in the account will be adjusted to the required indicators through rapid oxygen reduction or natural oxygen reduction. Measure the concentration of oxygen and carbon dioxide in the account every day or every other day. See Appendix B (standard appendix) for the preparation, storage and use of calcium hydroxide.

7 refrigeration conditions

7. 1 index of temperature, humidity and gas composition in cold storage

See table 1 for the temperature, humidity and gas composition indexes of the cold storage. See Appendix C (standard appendix) for the detection of various indicators.

Table 1 temperature, humidity and gas composition index of refrigerated garlic shoots

Project indicator

Product temperature (0.5)℃

The relative humidity of the warehouse is (85-95)%

The gas index plastic film accounts for 2-5% of oxygen.

Carbon dioxide (3-6)%

Plastic film bag oxygen (1-3)%

Carbon dioxide (10- 13)%

7. 1. 1 Plastic film bag can be refrigerated 150 days, the upper limit index can be used for carbon dioxide control, and the lower limit index can be used for oxygen; After 150 days, the lower limit index of carbon dioxide should be adopted. Oxygen takes the upper limit index.

7. 1.2 oxygen and carbon dioxide, as long as one of them meets the standard, the bag can be opened for ventilation.

7.2 Air circulation and air replacement

7.2. 1 Plastic film tents are refrigerated 2-3 times a week, and each cycle is (15-20)min.

7.2.2 In the cold storage where garlic shoots are refrigerated, the external low temperature at night should be used irregularly (2-3 times a month) to open the ventilation system or doors and windows to update the air in the cold storage, so that the temperature in the cold storage will not fluctuate greatly during ventilation. The air is updated to help eliminate excess carbon dioxide and other gases.

8 Cold storage period

Under the above technical conditions, the general cold storage period is (150-300) days. Failure to meet the above technical conditions will cause damage. See Appendix E (Recommended Appendix) for damage phenomena and preventive measures.

Appendix a

(standard appendix)

Specification for plastic film tents, bags and shelves

A 1 refrigerated shelf specifications

Take a plastic tent for storing (3,000-4,000) Jin of garlic bolts as an example. The shelf is (3000-4500)mm long, 1200mm wide and 3 150mm high, with 7-9 floors in total. The interlayer spacing is (300-400)mm, and the bottom layer should not be less than 250mm from the ground. The top of the shelf is arched, made of 40mm×50mm steel strip, and the vault is bolted on the basis of the shelf. If it is refrigerated in small plastic packaging, it depends on the height of the warehouse. But the top garlic shoot should be more than 500mm away from the cold air outlet.

A2 Specification for Plastic Film Curtains

A rectangular tent was made of nontoxic PVC film with a thickness of 0.23mm and covered outside the shelf. The size of the account depends on the reserve. Both sides of the curtain are provided with air holes, and both ends are provided with circulation openings. The bottom of the curtain should be paved when stored. The structure of the young garlic shoot storage account is 400mm longer than the height of the shelf when rolling a large rectangular account to match the bottom of the account and seal the edge of the account.

A3 film bottom specification

Using non-toxic PVC film with a thickness of 0.23mm, the account bottom with a width of (2100-2,200) mm and a length of (3,900-5,400) mm is made, and the large account is sealed.

A4 plastic film bag specifications

Use (0.06-0.08)mm polyethylene film to roll into rectangular bags with a length of (1000-100) mm and a width of (700-800)mm, and each bag will store garlic bolts (18-).

Appendix b

(standard appendix)

Preparation and storage of calcium hydroxide

B 1 calcium oxide (quicklime) is powdered calcium hydroxide (hydrated lime) after adding water, which will cool after losing a lot of heat.

Before use. The reaction formula is as follows:

Calcium oxide+water = calcium hydroxide

B2 Calcium hydroxide (hydrated lime) should be refrigerated under sealed conditions, otherwise it will fail because of absorbing carbon dioxide in the air.

Appendix c

(standard appendix)

Detection of various indexes of refrigerated garlic bolts

C 1 detection of gas composition

C 1. 1 Oxygen and carbon dioxide are determined by Austenite or other types of gas analyzer, and the determination method is as described by the gas analyzer.

C 1.2 If an austenitic gas analyzer is used, it shall be determined under the environmental conditions above 15. Liquid medicine preparation: alkaline solution: weigh 40 grams of potassium hydroxide, dissolve it in 60 ml of distilled water, and measure the carbon dioxide content.

Pyrogallic acid potassium solution: weigh 153g potassium hydroxide (KOH) and 3 10mL distilled water, then take 10g pyrogallic acid (1, 2,3-trihydroxybenzene) (C6H6O3) and 179mL distilled water for heating. Used to measure oxygen content.

Sealing solution: Take 200ml of 80% sodium chloride (NaCl) saturated solution, and add 2-3 drops of (0. 1- 1.0)N hydrochloric acid (HCl) and 3-4 drops of methyl orange. Make the solution appear red. Used for measuring in measuring tube.

C 1.3 calculation formula:

Gas sample volume before measurement (mL)- gas sample volume after measurement (mL)

Content of various gas components (%) = × 100...(C 1)

Total gas volume (ml)

Detection of C2 temperature

Insert the calibrated semiconductor thermometer, multipoint thermometer or mercury thermometer (scale value is 0.2) directly into the garlic shoot sample, observe the crystal temperature of garlic shoot regularly, and detect the temperature in the warehouse at the same time. The layout of test points should be reasonable. Thermometers are generally placed in the four sides and center of the library in a plum blossom shape.

Detection of C3 relative humidity

Use a calibrated dry and wet bulb thermometer, soak the wet bulb with distilled water, and measure the relative humidity in the warehouse with a self-recording hygrometer or a hair hygrometer. The hygrometer (meter) is placed in the central part of the library or observed at any time.

Appendix d

(standard appendix)

Sterilization and using method of thiabendazole

Some damages caused by environmental conditions are as follows:

Table E 1

Damage phenomenon, damage causes, related factors and preventive measures

The garlic bolt packaging bag contains slight oxygen deficiency or high carbon dioxide regulating gas components, so sell it as soon as possible.

The smell temperature of alcohol (ethanol) is too low, which is obviously frostbite after a long time, and it cannot continue after thawing.

Garlic seedlings are hard and dark green. Freezing point temperature leads to continuous cooling. If frostbite is slight, slow down.

In severe cases, the epidermis can still be refrigerated after slow thawing.

When bracts and stems become Huang Shi, the temperature is high, unstable or oxygen-containing. Strengthen temperature management and control gas.

Hair chaff, and there are ingredients that exceed the standard of mildew, check for leaks and fill gaps.

Bract swelling, bract high temperature or long-term high oxygen urge the control of gas composition, and check it in time.

The rancid smell is strengthened, and the bag will be replaced immediately because of humidity in the later period, which will reduce the pollution.

How low is the temperature of condensed water?

Mould grows on the shoot tip, which leads to incomplete precooling of garlic shoots, large fluctuation of water tank temperature, sufficient precooling, and the temperature of garlic shoots reaching the standard.

Pack more bags of condensed water in rotten bags, control the warehouse temperature and reduce quilts.

move

Dead buds and stem subsidence, low maturity, long-term hypoxia or gas composition adjustment, active organization.

Selling diseased spots and broken strips with high carbon dioxide.