How can blanched vegetables maintain their original brightness?

Green vegetables should be stored at low temperature (not less than 0) environment, if the temperature exceeds 40, the chlorophyll enzyme contained in it will separate the chlorophyll from the protein and be lost, if the temperature is lower than 0, the chlorophyll will be destroyed by freezing.

Green vegetables should be blanched quickly before stir-frying, and then quickly cooled with cold water. This is because the chlorophyll enzyme in vegetables can only lose its vitality above 90, thus losing the ability to destroy chlorophyll, and at the same time, it can also reduce the chlorophyll magnesium demagnesium and discoloration due to the phytic acid and oxalic acid contained in vegetables that have been heated for a long time, so that the bright green color of vegetables can be more durable.

If you add a little oil to the water when blanching, it can make the blanched vegetables more moist and green. Stir-fried green leafy vegetables should take the method of rapid stir-frying, usually the degree of magnesium removal reaction is increased with the extension of cooking time, cooking for 10 minutes, there is demagnesium chlorophyll generation, if cooking for 20 minutes, there is magnesium chlorophyll generation, the color of vegetables will be obvious yellow-brown. Therefore, stir-frying is used to reduce the cooking time and better preserve the green color of vegetables.

Although the temperature is high, the time is short, and the oxidase in the vegetable can be quickly inactivated, so the loss of vitamins is relatively small.

In addition, do not cover and simmer, because when the vegetables are cooked, the phytic acid and oxalic acid contained in them can be volatilized by heating by stir-frying, and if they are covered, they will condense on the lid and return to the vegetable pot, so that the chlorophyll will be demagnesiumized and turn brownish.

When blanching, just add some oil

Summary. While blanching, add two drops of oil to the water. This prevents oxidase from destroying chlorophyll and keeps the greens bright in color.

In addition, the temperature of blanched vegetables is relatively high, and after being fished out of the water, it comes into contact with oxygen in the air, resulting in thermal oxidation, which not only loses nutrients, but also easily changes color. Therefore, the blanched vegetables should be cooled in time, and they can be put into cold boiled water, but they should be removed immediately. It should be reminded that if the blanched vegetables are used directly for cooking, you can not use cold water, but you can't leave them in the air for a long time, and it is best to cook them immediately after removing them.

While blanching, add two drops of oil to the water. This prevents oxidase from destroying chlorophyll and keeps the greens bright in color. In addition, the temperature of blanched vegetables is relatively high, and after being fished out of the water, it comes into contact with oxygen in the air, resulting in thermal oxidation, which not only loses nutrients, but also easily changes color.

Therefore, the blanched vegetables should be cooled in time, and they can be put into cold boiled water, but they should be removed immediately. It should be reminded that if the blanched vegetables are used directly for cooking, you can not use cold water, but you can't leave them in the air for a long time, and it is best to cook them immediately after removing them.

Me: This is a factory processing of green vegetables, such as pine cabbage, rape, 98-100 water temperature blanching, low temperature - 18C below storage, a month of discoloration, how to extend the storage time.

Take spinach, for example.

Spinach is a round-leaved species with lush leaves. The raw materials are required to be fresh and tender, dark green, no yellow leaves, no diseases and pests, and a length of about 150 300mmThe interval between harvesting and freezing should be as short as possible, and the storage time should not exceed 24 hours

In the initial processing, it is necessary to select one by one, remove the yellow leaves, and cut off the roots; When washing spinach, wash it one plant at a time. The roots and leaves of spinach have different degrees of aging and moisture content, so the blanching time for the roots should be longer and the leaves should be shorter. Here's how:

Put the washed spinach roots down in the basket, and when blanching, first soak the roots in hot water and blanch for 30s, and then soak all of them in hot water and blanch for 1minTo maintain the strong green color of spinach, it should be quickly cooled to below 10 after blanching. The cooled spinach should be drained one by one, packed into a plastic bag every 500g bundle, placed on a sealing machine to seal, and then frozen at a low temperature of -30 for 20min

Quick-frozen spinach is very crispy and easy to break, so it should be handled with care when packing, generally one box per 20 bags.

This process is the same, we all know, there are other improvements, prolonged preservation inch.

Steam generators can be utilized. The steam generator uses a heating element to continuously provide heat to the boiler, and the high-temperature steam for vegetable finishing can be generated in two minutes after the equipment is turned on.

There are some vegetables that have to be blanched. In order to keep vegetables green, you should reduce the degree of magnesium removal reaction of vegetables, and pay attention to several points:

First, in the process of heating to open the lid, the reason is that when the vegetables are just exposed to high temperature, the green of the vegetables will increase and become green, if the green is continued to be heated, it will become yellow or brown, this is because the chlorophyll has undergone magnesium demagnesium action, especially in the acidic environment, it is easier to have a magnesium removal reaction, and organic acids will be released in the process of changing the spike to heat, which is the main substance that promotes the discoloration of vegetables; However, the lid of the pot can be opened to allow the organic acids to volatilize with the steam, thus reducing the degree of magnesium removal reaction of vegetables.

Second, when blanching, you should also pay attention to the blanching time should not be too short, some vegetables are not blanched thoroughly, and the result will be counterproductive. Because these fresh vegetables are still active in the tissues before they are heated, the substances of this activity are phenolases. If the blanching time is too short, the vegetables will not be blanched thoroughly, which will not achieve the purpose of inactivating the phenolase, but will promote the browning of the vegetables.

Third, the same blanching time should not be too long, too long will make the vegetables become dull, lose luster, and the locust reed pigment decomposes too much. Therefore, it is necessary to control and shorten the blanching time. In the past, the master added alkali or soda when blanching vegetables to increase the green of the vegetables, but it also destroyed the nutrition of the vegetables accordingly.

How to keep vegetables green after blanching them in the water wheel bureau, I think if you keep them green, you can put some salt when blanching the water, and Laqing will definitely be green when you copy it out like this. Differential type.

Many people will definitely choose to blanch vegetables before stir-frying, because blanching can sterilize and disinfect, and some vegetables are more colorful and beautiful after blanching. Therefore, blanching is a technical activity, which can not only reduce the pollution of residual pesticides, but also reduce the loss of nutrients in color, flavor and beauty. However, in fact, from a nutritional point of view, blanching will still cause the loss of some nutrients.

From a nutritional point of view, blanching can increase the loss of water-soluble nutrients. For example, blanching bok choy in 100 degrees of water for 2 minutes has a vitamin C loss rate of up to 65%; Blanched for more than 10 minutes, vitamin C is almost lost, and the cabbage eaten no longer has any nutrients. Therefore, blanching should be done in an appropriate way to minimize the loss of nutrients.

Blanching in boiling water for a short time:Blanching with boiling water for a short period of time can be used to reduce the heat loss of nutrients. Boiling water contains little oxygen, which reduces the loss of vitamin C due to thermal oxidation.

Add salt when blanching:When blanching, add 1% salt to the water to make the vegetables in the normal salt water solution, which can slow down the diffusion of soluble nutrients in the vegetables into the water.

Don't cut the blanching appetizer:Keep the vegetables as intact as possible, so that the area exposed to heat and water is reduced. In the case of a large number of raw materials, the materials should be fed in batches to ensure that the raw materials are in a higher water temperature.

Vegetables cool immediately after blanching:The temperature of vegetables is relatively high after blanching, and it comes into contact with oxygen in the air after leaving the water to produce hot oxygen, which is a continuation of nutrient loss. Therefore, the blanched vegetables should be cooled and cooled down in time.

A common method is to cool down with a large amount of cold water or cold air, which has less nutrient loss.

Boil water for a short time, add salt when blanching, try not to cut the vegetables before blanching, and cool the vegetables immediately after blanching. These are actually good ways to reduce the loss of nutrients and less loss of vegetables when blanching. Blanching vegetables is a good habit, but it also needs to be done in the right way, so that it can be healthy and delicious.