Cold storage technology of citrus

Citrus cold storage technology, citrus production is very large, citrus is generally harvested in11-65438+February. At this time, although the outdoor temperature is low, it can't reach the suitable storage temperature of citrus, and citrus can't be stored effectively. Let's take a look at citrus refrigeration technology.

Citrus cold storage technology 1 The suitable storage temperature of citrus cold storage is 3℃~9℃, and the relative humidity in the warehouse is controlled at 75%-95%. But the storage temperature of different varieties is different. Citrus can be stored in cold storage for 2-4 months, and the quality of citrus after long-term storage is close to that when it was just picked, such as oranges, oranges and oranges.

Long-term storage technology of citrus under cold storage;

Harvest citrus: choose to harvest it after dew in the morning, avoid bad weather such as rainy weather, manually harvest it, wear gloves, and handle it gently. Although the orange peel is thick, if it is damaged, it will affect the storage quality.

Choose citrus: There are more than 20 kinds of citrus diseases, so we should carefully select the fruits with diseases, insect bites, rot, deterioration and deformity to prevent the storage of other good fruits from being affected, and then package them in different grades according to the size and quality of citrus, so as to prepare for pre-cooling storage.

Pre-cooled citrus: this is also a point that people often ignore. Pre-cooling is an important work. Pre-cooling is to prevent citrus from deteriorating in time. Because citrus will consume its own nutrients after harvest and will gradually deteriorate, it should be precooled in time to make it quickly cool to a state suitable for storage.

Storage of Citrus: The precooled citrus can be directly stored in the warehouse, packed in cartons or piled in hollowed-out baskets. However, care should be taken not to over-squeeze, and enough space should be reserved to ensure that citrus can fully absorb the cold energy in the warehouse during storage.

When citrus is stored in the cold storage, it should be ventilated regularly, disinfected before storage, and then opened to cool down. When used later, it should be maintained, maintained and disinfected regularly to ensure the stability and safety of the cold storage.

Cold storage technology of citrus Ⅱ cellar storage

Cellar storage is a common storage method for sweet oranges, which is simple and cheap, and suitable for scattered storage by growers. The humidity in the basement is generally 95% ~ 98%, the temperature is stable at 12 ~ 18℃, and the concentration of carbon dioxide in the gas in the cellar is very high, reaching 4% ~ 6%. Such a natural storage environment is very conducive to maintaining the moisture of fruits and making them fresh, tender and round. Of course, the weight loss rate is low, and the storage period can last from May to July.

Basements are generally built inside and outside houses with high terrain and low groundwater. The basement of Nanchong City was built into a "triangular cellar" with a narrow top and a wide bottom. The diameter of the cellar hole is about 50 cm, the diameter of the cellar bottom is generally 2-2.5 m, the cellar depth is about 1.8m, and the cellar lock cap is 3-5 cm thick. Generally, the lid is opened every 7 ~ 10 days to ventilate and pick up rotten fruits.

Ventilation storage

Ventilation storage belongs to normal temperature storage, which is the most common storage method of citrus in South China. Ventilation storage has the advantages of storing more fruits, convenient operation and low engineering cost, and is suitable for large-scale commercial service storage.

Spontaneous inflatable packaging and storage

As early as 30 years ago, scientific research was carried out in China, and citrus was stored by plastic film sealed rice A storage method. Put oranges in plastic film tents (bags) first, and then put them in ordinary houses, ventilated warehouses, earth caves and other storage places. Plastic film tents are generally made of 0.2 ~ 0.25 Ra meters and bound into rectangular tents. The volume depends on the storage capacity, generally 500~ 1000Kg. Because the concentration of carbon dioxide suitable for storage of citrus fruits is 2% ~ 4%

In order to avoid carbon dioxide poisoning, people are usually drawn out from the gap at the bottom of the account to absorb carbon dioxide, or the account door is opened on time for ventilation. Spontaneous inflatable packaging can also use plastic bags to package oranges, and then seal the bags to achieve the purpose of inflatable packaging. Plastic packaging film is usually made of polyethylene film, which automatically balances the waste gas components in the bag through the inhalation of goods and the permeability of plastic film itself.

Fresh-keeping method of citrus

Garlic solution to preserve citrus: Mash a garlic clove, put it into 10 part of boiling water, mix, take the solution, cool it to room temperature, then soak the selected citrus in garlic solution, take it out to dry for 10 minutes, and put it in a box or a packaging bag for preservation, which can keep fresh for 3 months. Fresh-keeping citrus with natural soda water: Mix 2 parts of baking soda 1 part of water diluent into liquid, soak in citrus for 2 minutes, take it out and dry it, put it in a packaging bag and seal it, which can keep citrus fresh for 3 months.

The cold storage technology of citrus lies in that it can keep the trees fresh. This method has the best fresh-keeping effect on citrus. Secondly, you can pick the fruit, soak it with preservative, spread a tarpaulin on the ground and store it in a ventilated and cool place, usually about ten days, so that the problem of dry fruit stems will not occur. In our countryside, it is cypress leaves that cover the fruit, and it is better to cover the fruit with a bag for two months. Sealed with plastic wrap, the cold air storage effect is very good.

Generally, straw can be laid for storage. You need to prepare a carton or wooden box first, then lay a layer of straw on the bottom of the box, then put Puckilo on the straw, and finally lay a layer of straw on Puckilo.

When storing oranges, the skin should be kept dry, and it is best to store them in a place with slightly lower temperature and clean ventilation. In this way, the storage time of oranges in this environment is about one week. After more than a week, oranges began to lose water and began to rot. The main component of oil is allicin, which is produced by the decomposition of allicin in fresh garlic, including allicin and allicin. Allicin can inhibit and kill anthrax, Rhizoctonia solani, Rhizopus and other fungi.

It can be kept for a long time in winter. If it is kept dry in a ventilated place, it can be kept for about a week. Oranges had better not be put in the refrigerator. Oranges can be stored in places with low oxygen and few clean bacteria, such as crisper.

Therefore, in order to make oranges storable, the first step is to choose oranges with relatively good quality. In addition, if there is a layer of gray substance on the surface of oranges, it is actually more resistant to storage under natural conditions, indicating that it was not cleaned during picking and transportation. The specific preservation method is to pick out the picked oranges, put the rest in a slightly dry place, then sprinkle with thick skins or wheat skins, and finally spread a layer of straw, and dig a few when you want to eat.