Preservation methods of spinach

Spinach is rich in nutrients, especially fresh and delicious in spring, but in fact spinach from picking to being placed on the table, because of improper preservation and loss of nearly half of the nutrients, then spinach how to preserve it? Let's take a look at how spinach is preserved!

How to buy spinach

1. It is better to buy red and short vegetable stems and fresh and elastic leaves.

2. Choose spinach with thick leaves, good extension, wide leaves and short petioles. If the leaves are discolored, they should be removed.

How to preserve spinach

Spinach is extremely perishable, as long as it is above freezing point (close to 0℃), the lower the temperature, the longer the storage period, close to 0℃ storage, can be stored for about three weeks. As storage temperature increases, the shelf life decreases rapidly.

During transportation, crushed ice can be used and placed on spinach to achieve rapid precooling effect. In addition, attention should still be paid to the maintenance of humidity to prevent dehydration, but no condensed water attached to the leaves, so as not to increase the rate of decay. Spinach can be stored in perforated plastic bags to reduce moisture loss and physical damage. Atmospheric storage of 10 - 40% CO2 and 10% O2 can prevent leaf yellowing and maintain quality.

Winter storage spinach method 1, ordinary frozen storage method: spinach that needs to be refrigerated is generally frozen on the ground at night, and can be thawed at noon. Harvest with about 1.6 cm long roots, shake the soil, arrange the bundle, each bundle of about 2 kg, put in the shade to dry dew, and make the vegetables cool, wait for the cold weather frozen storage. The storage site should be selected in the shade, level the ground, dig a number of trenches 3.5 cm wide and deep, the trench spacing is 10~15 cm, the spinach root is placed in the trench, the total thickness is about 25 cm. In the cold season, it can be covered with grass and so on, and the temperature in the ditch is kept at-8~-5℃.

2. Freezing method of spinach without ventilation channel: In the shade area north of the house or shade, dig several trenches parallel to the shade, the width of the trench is 25~30 cm, the depth is the same as the height of spinach or slightly shallow, and the distance between the trench and the trench is about 20 cm. Place the pre-stored spinach bundles upright with roots down in the ditch, and sprinkle dry soil on the bundles. The thickness of the soil should just cover the spinach. Later, with the drop of temperature, the soil should be covered in different times, and the soil should be smooth and seamless, so as to play the role of wind prevention and moisture retention. The principle is that the temperature in the bundle should be kept at-4~-6℃ as much as possible, so that spinach is slightly frozen.

3. Freezing storage method on the ground: 5~6 days before harvest, level the site and pour a layer of water to ensure that the topsoil does not thaw. When storing vegetables, first sprinkle some leaves or leaves at the bottom, then put spinach bundles on top, and then cover the vegetables with leaves or leaves 10~12 cm thick. When the spinach is frozen inside, cover it with 10 cm of semi-dry sand to prevent the leaves from losing water.

4. Bagged spontaneous atmosphere refrigeration method: Bundling the harvested spinach into 0.5 - 1.0 kg spinach bundles, cooling and precooling, placing the spinach bundles into polyethylene film bags with the thickness of 0.06 - 0.08 mm and the specification of 110 * 80 cm, wherein the leaves are opposite to each other, the roots face the two ends of the bags, each bag is about 15 - 20 kg, sending the spinach bundles to a vegetable rack of a cold storage, laying the spinach bundles horizontally, opening the spinach bundles and precooling the spinach bundles for one day and one night, inserting a round rod with the diameter of about 2 cm into the bag mouth and fastening the spinach bundles, pulling out the round rod or loosening the bag mouth, A large gap is left in the bag, and the bag is sealed and placed in a cold storage with a temperature of-1 DEG C and a relative humidity of 90 to 95 percent. A gas environment with lower oxygen and higher carbon dioxide can be gradually formed by the spontaneous metabolic activity of spinach in the bag. Meanwhile, the internal humidity condition is good, and the freshness can be kept for 2 to 3 months without much loss.

5. Combined ridge frozen storage method: Select the plot with strong spinach growth and the combination of combined ridge frozen storage. Each combination has three ridges, of which the left ridge and the right ridge are vegetable ridges, and the middle ridge is frozen storage ridge. Before frozen storage, first use a shovel to shovel the frozen vegetable roots, the depth of 1.5 cm into the soil is appropriate, do not disturb the whole shovel vegetable plants. In the same way, scoop up the spinach from the left and right rows, cover it with the frozen storage in the middle, with the leaves facing down and the roots facing up. The spinach from the three rows is combined into one row. On the day of storage, the surface of the combined ridge is buried tightly with soil, and the upper and lower layers of spinach are gently tapped to prevent cold wind from entering. When the temperature is too low, a layer of fine soil 7~10 cm thick is covered. This method can be used to store until the spring equinox of the following year.