Blanching is not simply boiling! These 6 types of foods that must be blanched, you may not have blanched them all the time......

Blanching, a common process when cooking, but do you really know how to blanch? Which ingredients need to be blanched, do it need cold water or hot water? Blanching is healthy and life-saving if you do it right, and if you do it wrong, the nutrition and taste will be greatly reduced~

Today, we will take a look at the ingredients that need to be blanched and how to blanch them correctly.

What ingredients need to be blanched?

Vegetables high in oxalic acid

Oxalic acid is an antinutrient found in many vegetables, but there is a difference in the amount. Excessive intake of oxalic acid in the daily diet can form insoluble substances with calcium before absorption, hindering the absorption of calcium, and after absorption, it can form insoluble oxalate with calcium and other substances in the body, increasing the risk of stones.

Vegetables such as Chinese cabbage, small white radish, cabbage, mung bean sprouts, carrot tassels and other vegetables are very low in oxalic acid and can be eaten with confidence. Vegetables such as spinach, water spinach, celery, amaranth, and purslane are relatively high in oxalic acid, and they need to be removed through certain pretreatment before eating.

Fortunately, oxalic acid is easily soluble in water, and blanching in hot water can remove most of the oxalic acid. Studies have shown that the removal rates of soluble oxalic acid were 43%, 50%, 54.7% and 58.9% when 180g of spinach was blanched in 1000ml of boiling water for 1 minute, 2 minutes, 3 minutes and 4 minutes respectively. The removal rate of oxalic acid in spinach is not high, not more than 5%, even if the amount of cooking oil is increased, it has little effect.

In addition, purslane is special, its oxalic acid content is as high as 1460mg/100g, more than twice that of spinach. Experiments have shown that 100g purslane 500ml blanched in water for 3 minutes, oxalic acid removal rate can reach more than 50%, blanched for 4 minutes and then discarded soup to eat, oxalic acid content is 560mg/100g. Although the oxalic acid content is lower than that of fresh spinach, it is still higher than that of most green vegetables, so it is better to eat less.

There are "poisonous" vegetables

Some vegetables are born with toxins, and if not blanched or eaten raw, they may cause food poisoning, which can be fatal.

1. Beans, green beans

Raw beans and green beans contain saponins, which contain hemolysin that can destroy red blood cells, which has a strong stimulating effect on the mucosa of the gastrointestinal tract, causing congestion, swelling and hemorrhagic inflammation, which can cause nausea, vomiting, abdominal pain, diarrhea and other symptoms.

This ingredient is more sensitive to heat, heated at 100 °C for more than 10 minutes, or at a higher temperature when fried thoroughly can cleave saponins to eliminate the toxicity of harmful substances. Blanching before cooking is a good way to avoid poisoning.

2. Fresh daylily

One of the ingredients in fresh daylily can cause nausea, vomiting, dry mouth, and diarrhea when consumed.

As for what this ingredient is, it is not clear at this time. In the past, people thought that it was colchicine, but the latest research put forward different views on the "toxic components" in daylily, that daylily does not contain colchicine, but contains the co-elution components of multiple compounds, which are easily soluble in water, and can be decomposed by steam and blanching, and can be safely eaten after 3~5 minutes of boiling water treatment.

Vegetables high in nitrites

When it comes to "nitrite", many people think of "carcinogenic". In fact, nitrite itself is not carcinogenic, but after it is eaten into the body, it will produce nitrosamines in the environment of stomach acid, nitrosamines are carcinogens, and excessive intake will increase health risks.

Therefore, vegetables with high nitrite content must be blanched before cooking. Some researchers evaluated the health and safety level of vegetables in a suburb of Shanghai, and found that the nitrite content in fresh vegetables was generally low, the highest nitrite content in leafy vegetables was 19mg/kg, the nitrite content of onions, garlic, melons, beans, aquatic and nightshade vegetables was lower, and the nitrite content of some vegetables was less than 0.1mg/kg.

Although they can be eaten with confidence, the nitrite content of leafy vegetables is higher than that of other vegetables, and the nitrite content of toon in leafy vegetables is more prominent. Don't worry, though, blanching can reduce the nitrite content in vegetables.

Someone bought 6 toon samples from farmers' markets and supermarkets, the nitrite content is 100~500mg/kg, and more than 50% nitrite can be removed after washing 3 times, and the nitrite content is 50~200mg/kg, blanching for 1 minute can remove more than 90% of nitrite, and its nitrite content is 10~50mg/kg.

Therefore, don't eat dipping sauce again for toons, even if it's scrambled eggs, you have to blanch them first.

Vegetables that may be contaminated with parasites

Aquatic plants are likely to be contaminated by parasites, such as water chestnuts, lotus roots, and water chestnuts that we often eat, don't use them directly to make cold dishes, they are likely to be infected with ginger fasciola, mild abdominal pain, diarrhea, nausea and fever, and in severe cases, intestinal obstruction, and even death.

Blanching the water and then cold dressing can ensure food safety.

Vegetables that are not easy to clean

The surface of some vegetables is uneven, and there are many potholes, which are easy to hide dirt and dirt, and are also more prone to pesticide residues. For example, broccoli, cauliflower, and fungus are not easy to clean, and there may be soil and insect eggs in the crevices.

However, broccoli is relatively rich in vitamin C in vegetables, and the blanching time should not be too long to avoid the loss of vitamin C, and it can be blanched for 1~2 minutes.

Foods that are stained with blood or have a peculiar smell

Animal foods such as pork ribs, lamb, and pork intestines may carry blood stains or odors, and blanching can reduce their effects and improve the quality of dishes. At the same time of blanching, you can add cooking wine, bay leaves, star anise and other spices to remove the smell and increase the fragrance.

Things you need to know before blanching

Blanching seems simple, it seems to be a matter of "boiling water + ingredients", but there are many precautions in actual operation.

1. Cook meat under cold water, seafood and vegetables in hot water

Meat foods need to be served in a pot under cold water to help skim off the blood foam. If the pot under boiling water will denature the protein on the surface of the meat, the outermost layer will be cooked directly, resulting in the blood and water inside not coming out, and the purpose of removing blood stains will not be achieved, and the taste will not be good.

Vegetables need to wait for the water to boil before putting them in the pot. Although cold blanching has a higher removal rate than hot blanching, cold blanching will cause the physical structure of vegetables to be destroyed as much as possible and more nutrients will be lost.

It is recommended to blanch the fish and shrimp in boiling water for 1~2 minutes and then remove them, which can not only remove the fish, but also maintain the tender taste.

2. Water volume required foot 够

It is best to submerge the ingredients with water, so that the water in the pot can boil again in a short time after the ingredients are added, shortening the cooking time and reducing the loss of nutrients.

3. The blanching time is different for different ingredients

For most leafy vegetables, you only need to blanch for 1 minute, and it is recommended to blanch the vegetables first and then cut the vegetables, and immediately put them in cold water to cool down and drain them after blanching, so as not to squeeze them too much to avoid nutrient loss.

Vegetables like bamboo shoots and coconut white can be boiled for a while. This is because the total oxalic acid removal rates of bamboo shoots and coconut white were 60% and 10.7% when blanched for 1 minute, respectively, and 63.9% and 31.7% for 3 minutes of boiling, respectively. At the same time, they themselves are afraid of heat vitamin content is also very small, bamboo shoots, coconut white vitamin C content is only 5mg/100g, vitamin B group is not more than 0.1mg/100g, do not worry about the loss of this kind of nutrition.

Blanch broccoli, cauliflower, fungus for 1~2 minutes, water chestnuts and lotus roots should be blanched in boiling water for more than 1 minute, beans and green beans should be blanched for more than 10 minutes, and fresh daylily should be blanched for 3~5 minutes.

After the meat is put into the pot, wait for the water to boil again, and cook for another 1~2 minutes until there is no large amount of blood foam to cook out.

4. If you want to maintain the color of vegetables, you can put a few drops of cooking oil when blanching

5. Don't reuse the water from the blanched food

Oxalic acid is soluble in water, and the longer the blanching time, the higher the oxalic acid content in the soup.

If you don't know if the vegetables you want to eat need to be blanched, then just make boiled dishes. After the vegetables are out of the pot, drain the water, add some steamed fish soy sauce or light soy sauce, and drizzle with sesame oil or flaxseed oil, it is a delicious dish! Boiling belongs to low-temperature cooking, compared with frying, frying, and frying, it can retain more nutrients, and also avoid the production of harmful substances, which is quite recommended!

Source: Popular Science China