Application of fresh-keeping Technology in garlic for Export

Garlic is one of the main varieties of agricultural products in China, with an annual export of about 300000 tons. Among them, refrigerated (fresh) garlic accounts for about 60% of the total export volume. Therefore, whether the fresh-keeping technology is mature or not has a direct impact on the quality of export fresh-keeping garlic.

I. the fresh-keeping principle of garlic

After the scales developed and matured, garlic entered a dormant period of 2 months, during which it did not germinate even under suitable environmental conditions such as temperature, humidity and gas composition. After the dormant period, the coleoptile and bud primordium began to grow, and the buds germinated gradually under suitable conditions. The storage and preservation of garlic is actually after the dormancy period of garlic, take necessary measures to cause its growth conditions are not suitable, so as to force it to continue dormancy. That is, through appropriate low temperature, hypoxia and other measures to restrain its life activity intensity, reduce its material consumption rate, and maintain its original fresh state.

Second, common storage and fresh-keeping methods of garlic

(1) High temperature storage. Placing garlic in a higher temperature between 28 ℃ and 32 min can keep it from germinating and prolong its storage time, but this method is only suitable for short-term storage, because garlic is easy to lose water, hair bran and dry shrink.

(2) low humidity storage. Mechanical refrigeration (constant temperature storage) was used to reduce the temperature, inhibit its life activity and control the germination of scale buds. This method is widely used at present.

(3) controlled atmosphere storage. Making use of the inhibitory effect of gas environment on life activities, the gas composition can be adjusted under suitable low temperature conditions to achieve the purpose of fresh-keeping.

(4) irradiation preservation. It is suitable to store garlic for a long time by irradiating garlic with C0 γ rays to inhibit buds, kill insects and sterilize.

3. Main technical conditions for constant temperature storage and preservation

(1) the quality of garlic. The quality of garlic used for storage should be strictly controlled, and garlic with no mechanical injury, no moth, no mildew, normal skin color, symmetrical size and non-loose cloves should be fully exposed to the sun and even dried.

(2) storage time and storage temperature. The storage time of garlic should be completed at the end of July or early August before the end of its physiological dormancy period. When entering the warehouse, the use of high-density plastic woven bags can not only reduce bumping, but also have the effect of moisturizing and gas retention. Garlic has a strong ability to endure low temperature, and freezing injury will not occur at-7 ℃ in a short time. The storage temperature of garlic should be controlled between-2.5 ℃ and 3.5 ℃ in the later stage. When the temperature difference is controlled within 1 ℃, excessive temperature difference can easily stimulate the activity of enzymes, stimulate life activities, and then sprout or lose weight.

(3) humidity. The relative humidity of garlic storage and preservation is between 70% and 80%, too high humidity is easy to mildew, too low is easy to lose water, and weightlessness causes "hair bran". In the process of storage, due to the frosting of the condenser and other reasons, the environmental humidity in the reservoir will gradually decrease, so it is often necessary to replenish some water, commonly known as "Sheung Shui". The common method of "Sheung Shui" is to spray saturated lime water or salt water on the ground, which has a low freezing point and has a definite germicidal effect.

(4) Gas composition. Garlic has a strong ability to tolerate carbon dioxide, up to 16%. During storage, the oxygen concentration can be controlled between 12% and 15%, and the oxygen concentration should not be less than 1%, otherwise garlic will be poisoned and deteriorated.

IV. Daily management

(1) measure the composition of the gas regularly and irregularly, and arrange the ventilation time reasonably to prevent the deterioration of garlic caused by carbon dioxide poisoning.

(2) the storehouse door shall be managed by special personnel, and it is forbidden to enter or leave at will, so as to prevent the infection of germs and the phenomenon of "cold leakage".

(3) pay attention to the temperature near the fan and air duct to prevent garlic frostbite, and timely measures should be taken to cover it with straw curtains or sacks when problems are found.