Storage and fresh-keeping Technology of garlic Bolt

Garlic bolts are nutritious, with a crude protein content of about 10%, sugar 8%, vitamin C 20-30 mg per 100 grams, calcium 20 mg, phosphorus 45 mg, iron 1 mg. In addition, garlic bolts are also rich in allicin. Therefore, it is welcomed by the majority of consumers.

I. Storage characteristics and varieties

Garlic stalk is the young flowering stem of garlic. Postharvest metabolism is exuberant, the surface of bolting is lack of protective tissue, and the temperature is high during harvest, so it is easy to lose water, aging and decay, garlic bolts become yellow and empty, fiber increases, bolting buds expand and crack, aerial bulbs grow, and edible quality is reduced.

Garlic bolts are produced in Yongnian in Hebei, Acheng in Heilongjiang, Qishan in Shaanxi and Jingchuan in Gansu. However, the quality of garlic bolts in Cangshan and other places in Shandong Province is the best. The stem is thick and long, so it is suitable for long-term storage. Garlic bolts can only be stored for 20 ~ 30 days at room temperature, but they can be stored for 7 ~ 10 months by refrigerated atmosphere storage.

Second, storage conditions

The storage temperature of garlic bolts is 0: 0.5 ℃, the relative humidity is 85%-95%, the oxygen concentration is 2%-5%, and the carbon dioxide concentration is 0%-8%. In the process of storage, as long as one of the two indexes of oxygen and carbon dioxide reaches the limit standard, it is necessary to open the bag immediately and the time for each change of air is 2-3 hours. The concentration of oxygen and carbon dioxide in the bag or account should be measured every day or every other day (only the representative bag). When the concentration of carbon dioxide exceeds the upper limit, it can be absorbed by hydrated lime. Hydrated lime can be made with quicklime and water, and can not be used until the pulverized hydrated lime is cooled and cooled. Hydrated lime should be stored under sealed conditions, otherwise it will fail due to the absorption of carbon dioxide in the air.

III. Preparation before harvest and storage

1. Harvest

Garlic bolts are generally harvested in May, when the temperature is higher. Seedling lifting should be avoided at noon, as far as possible to prevent strip breakage and damage to bolting. The harvested garlic bolts are tied into small bundles, packed in gunny bags or other packaging containers, and immediately transported to the cold storage for pre-cooling.

2. Preparation before storage

Garlic bolts should be disinfected in cold storage and utensils before entering the storage. they can be fumigated with 10 g / m3 of sulfur or sprayed with 1% 2% formaldehyde. After sealing for 20 to 48 hours, ventilation will remove the residual smell. Other utensils are soaked in 0.5% bleach solution and dried. Pre-cool the cold storage to 0 ℃ before the garlic bolts are put into storage. Garlic bolts should be stacked immediately in pre-cold room, cold storage or cool and ventilated place, remove field heat and breathing heat, wait for garlic bolts to be cooled to 0 ℃, then carry out pre-storage processing and finishing, processing should be carried out in cold storage or through the hall, pick out sick and damaged bolting strips, align the bolting buds of healthy bolting strips, and tie them with plastic rope at the stem 3-5cm away from the bolting bud, each bundle weighs about 0.5~l.0 kg. Cut off the tip of the bolting tip and keep the bolting tip which is 4cm long, or you can not cut the bolting tip.

IV. Storage methods and their management

1. Natural oxygen reduction and cold storage in plastic film bags

When the bolting temperature is o ℃, put the bolting tip outward and put it in a polyethylene or PVC plastic bag with a thickness of 0.06 to 0.08mm, a length of 100cm to 110cm and a width of 70cm to 80cm. Each bag contains 18kg of garlic bolts, tighten the mouth of the bag and place it on a shelf or in a packing container. When the oxygen in the bag is reduced to 1% 2% and the carbon dioxide is about 12%, the oxygen in the bag will be increased to more than 18%. The carbon dioxide is reduced to about 1% or 2%, and then the bag is re-sealed. The venting period of garlic bolts stored in o ℃ cold storage is about 10 to 15 days. In the middle and later stage of storage, the venting period was gradually shortened to 7-10 days.

2. Controlled atmosphere cold storage of plastic film silicon window bag

When the bolting temperature is 0 ℃, the bolting is slightly outward in the same thickness, length and width as the plastic film bag mentioned above, but embedded in a silicon window bag with an area of 9 × 13 cm silicone rubber window. Placed in the vegetable shelf or packaging container, because the silicon window bag has a certain permeability to oxygen and dioxin carbon, it can basically meet the gas composition requirements of garlic bolts, so it is not necessary to open the bag for ventilation during storage.

3. Controlled atmosphere cold storage of plastic film account

When using polyethylene or PVC film tent for controlled atmosphere storage, it is necessary to spread 0.23 mm thick film on the floor of the cold storage. the length and width coincide with the length and width of the stack or shelf in order to seal the tent. The processed and pre-cooled garlic bolts are packed into plastic boxes of 20 kilograms each, stacked on top, and a rectangular tent made of 0.23 mm thick film is used to cover the outside of the box stack. When withholding the account, 3 empty boxes are placed on the top of each stack, or the top of the account is made into a ridge line to prevent condensation water from dripping. After the plastic curtain is fastened, roll up its edge with the plastic film laid on the ground and press it tightly with bricks or other objects to create a sealed environment. Inflatable and suction cuffs and suction nozzles should be left on both sides of the plastic tent. After closing the account, the molecular sieve nitrogen machine can be used to adjust the gas composition and inject nitrogen into the bag. Rapid oxygen reduction, so that the oxygen content in the account can be rapidly reduced to the suitable range of garlic bolts, and it can also be reduced naturally. The respiration of garlic bolts was used to reduce the oxygen content in the account. Add appropriate amount of hydrated lime to the account to absorb the excess carbon dioxide. Fresh air can be breathed in when the oxygen in the account is too low. Due to the high temperature in the plastic bag or plastic tent, it is easy to cause the reproduction of microorganisms. 0.5 ml / L sec-butylamine can be added to prevent the growth of self-mold or black mold.