Why do mung beans turn black after being boiled in an iron pot?

Mung beans, also known as leguminous mung bean seeds, contain starch, protein, and dietary fiber.

Carotene, vitamins.

Calcium, potassium, magnesium, iron, zinc, selenium and other nutrients, as well as functional oligosaccharides, flavonoids, sterols and other functional ingredients. It has high nutritional and health value, and is considered an important food, a good medicine to help the world and clear away heat and heat.

Traditional Chinese medicine believes that mung beans are sweet and cool, and have the functions of clearing heat and detoxifying, dissipating heat and annoyance, diluting water and reducing swelling, relieving gallbladder and nourishing the stomach, moistening the intestines and laxatives, lowering blood sugar, lowering blood pressure, lowering blood lipids, anti-tumor, anti-allergies, protecting the liver and cardiovascular system, and enhancing immunity.

Lead displacement and other effects. It is suitable for summer polydipsia, internal heat, poor urination, edema, etc. Mung beans turn black when cooked in an iron pot because it contains tannic acid.

Tannic acid can react with iron to form black iron tannin.

Mung beans are boiled in an iron pot and will produce some black iron tannins that will turn black. Sometimes, even if bananas and apples are not cut with an iron knife, there will be some black spots on them because of tannins.

The molecule contains many phenolic hydrocarbon groups, which are sensitive to light and are easily oxidized to black oxides by oxygen in the air. Mung bean soup.

If the mung bean soup turns black due to too long storage, the first thing to judge is whether the mung bean soup is spoiled.

If it has not deteriorated, it can still be consumed without adverse effects on the human body. However, if the blackened mung bean soup also has a spoilage reaction, it is not suitable for continued consumption, otherwise it will produce an uncomfortable reaction. The reason why mung bean soup turns black is mainly because of the following two reasons: first, mung bean soup cooked in an iron pot contains more tannins.

If mung bean soup is boiled in an iron pot, the tannic acid will react with the iron to form black iron tannin, resulting in a black color of mung bean soup. The second reason is that mung bean skin stored for a long time contains polyphenols, which are easy to oxidize and discolor after contact with oxygen.

Therefore, if the mung bean soup is not properly sealed during storage, the color can easily turn black after storage for a period of time. Mung bean soup is an indispensable drink for cooling heat in summer. Most of the active ingredients in mung bean are in mung bean skin.

The flavonoids and metal ions in mung bean skin may form darker complexes when they react.

The color of mung bean soup turns black, and after eating, it will cause indigestion in the stomach and intestines.

Therefore, it is best not to use an iron pot when making mung bean soup, but to use a casserole or stainless steel pot.

It's because there are some toxic substances in it, so it turns black. So be sure to pinch the time during the cooking process.

This is because a chemical reaction occurs, and some elements in mung beans react with oxygen after cooking, so they change color.

Because like mung beans, it can be oxidized. When the mung bean encounters some rust in the iron pot, it will oxidize immediately, turning the water black.

The reason why mung bean soup turns black is mostly considered to be due to the following two reasons:

1. Boil in an iron pot.

Mung bean soup contains a lot of tannin components, if you cook mung bean soup in an iron pot, the tannin in it will react with iron and combine to form black iron tannin, resulting in the black color of mung bean soup.

2. Store for too long.

Mung bean skin contains polyphenols, and this silver mold is easy to oxidize and discolor after contact with oxygen, so if the mung bean soup is not sealed properly when stored, its color will be easy to turn black after a period of storage.

If the mung bean soup turns black because it is boiled in an iron pot, then it can still be eaten. If the mung bean soup turns black due to too long storage, then the first thing to judge is whether the mung bean soup is spoiled, if it is not spoiled, then it can still be eaten and will not adversely affect the human body, but if the blackened mung bean soup also has a deterioration reaction, then it is not suitable to continue to eat, otherwise there will be an uncomfortable reaction.

No. One of the reasons: Cooked in an iron pot, mung bean soup contains more tannins. If it is boiled in an iron pot, the tannic acid in it will react with the iron and combine to form black iron tantalate, which will cause the mung bean soup to turn black in color.

Reason 2: If stored for too long, mung bean skin contains polyphenols, which are easy to oxidize and change color after contact with oxygen. Therefore, if mung bean soup is not properly sealed during storage, its color can easily turn black after being stored for a period of time.

In the hot season, drinking mung bean soup can clear the heat and relieve the heat.

Mung bean soup is highly nutritious and contains protein, fat, trace elements, vitamins and crude fiber. Drinking mung bean soup in summer is good for your health.

When cooking mung bean soup, the choice of utensils is important. It is best not to cook mung bean soup in an iron pot or aluminum pot, because the flavonoids contained in mung beans will react chemically with iron ions and aluminum ions, making mung bean soup black, and its antioxidant and therapeutic effects will be weakened.

When boiling mung bean soup, it is best to cook it in a stainless steel pot. In order to make mung beans more likely to rot, you can first soak them in water in a thermos bucket for a period of time or so, about 3 hours. Then add the right amount of water to the stainless steel pot.

Once the water is boiling, pour the soaked mung beans into the pot. This seeps which chain like a chain and the mung bean soup can be cooked in about 3 minutes. And the mung bean soup does not change color.

When boiling mung bean soup, a lot of mung bean skin usually falls off, and the effect of mung bean skin is also very good. It's better not to throw it away.

When cooking mung bean soup, the ratio of allergic water to mung beans is usually 1 part mung bean and 10 parts water.

The mung bean soup boiled in an iron pot is dark and cannot be drunk. Since mung beans contain an ingredient called tannin, if mung bean soup is cooked in an iron pot, the tannic acid in mung beans will react with iron and combine to form black iron tannin, which will cause mung bean soup to be black in color and have a special smell.

It is recommended to use a clay pot or a stainless steel, rice cooker or other pots to cook mung bean soup.

Mung bean soup has changed flavor and rancidity, so it is not suitable to continue to eat.

Mung bean skin contains polyphenols, which are prone to oxidation and discoloration when in contact with oxygen.

Reason why the iron pot boils and turns black:Iron is easy to precipitate iron ions and react with other salts and acids to form iron compounds, which are most obvious in acidic foods, such as spinach and tomatoes.

Cooking mung bean porridge in an iron pot will cause the mung bean soup to appear black because mung beans contain a substance called tannin, which reacts with the iron ions in the iron pot to form a black iron tannin complex, which gives the mung bean soup a black color. The following is explained from two aspects: the list of ingredients and the steps to make it:

1.Ingredient list: The ingredients for mung bean porridge include mung beans, rice, and water.

Among them, mung beans are rich in tannins, while rice and water do not contain this substance. As a result, the tannic acid reacts with the iron ions in the iron pan to form a black ferric tannins complex, which causes the mung bean porridge to turn black.

2.Production steps: When using an iron pot to cook mung bean porridge, first put mung beans and rice into the pot in a certain proportion, and then add an appropriate amount of water.

Next, heat over medium heat, stirring constantly, to prevent the bottom from sticking. When the rice boils, turn to low heat and continue to cook for about 30 minutes. During the cooking process, mung beans are rich in green leaf pigments, which are prone to browning at high temperatures, resulting in the color of mung bean soup gradually becoming darker.

If cooked for too long, the mung bean soup may turn black.

To avoid the mung bean porridge from turning black, here are a few ways to consider:

1.Use pots and pans made of other materials, such as stainless steel pots, non-stick pots, etc., and avoid using iron pots to cook mung bean porridge, which can reduce the reaction with iron ions, thereby reducing the possibility of mung bean soup turning black.

3.Add lemon juice or vinegar: Adding an appropriate amount of lemon juice or vinegar when cooking mung bean porridge can neutralize the tannic acid and reduce the reaction with iron ions, thus avoiding the mung bean soup from turning black.

4.Use a pressure cooker: Use a pressure cooker to cook mung bean porridge to shorten the cooking time while maintaining the nutrients and color of the mung beans.

In conclusion, when cooking mung bean porridge, avoid using an iron pot, choose the right pot and shorten the cooking time and other methods can effectively prevent the mung bean soup from turning black. At the same time, maintaining good cooking habits and paying attention to the combination of ingredients can also help maintain the deliciousness and nutritional value of mung bean porridge.

Because mung beans contain elemental tannins, they will turn into black tannin iron when exposed to iron at high temperatures, which makes mung bean soup black and has a special smell, which not only affects appetite and taste, but also harms the human body.

Even stainless steel is rich in iron, so use it with caution. Because mung beans contain elemental tannins, they will turn into black tannin iron when exposed to iron at high temperatures, which makes mung bean soup black and has a special smell, which not only affects appetite and taste, but also harms the human body.

Even if it is stainless steel, it is also rich in iron-containing elements, so it should be used with caution.

Unless your pot is not a stainless steel pot, it is an iron pot. Mung beans should not be boiled in an iron pot, otherwise tannin iron will be formed and the soup of the mung beans will turn black.

Boil the mung bean soup in cold water, and then the soup will be red after the soup is soft. Add water to a stainless steel pot, bring to a boil, add mung beans, and cover the pot. After three minutes, scoop out the soup with a soup spoon and put it in a bowl.

The soup is yellow-green, clear and transparent. This is the true color of mung bean skin boiled. It contains a lot of polyphenols, which will change color when they see oxygen.

Boiled in a pot with boiling water and covered with a lid so that it does not come into contact with oxygen, so it can remain green for the time being. In this green mung bean soup, the polyphenols dissolved in the bean skin have not yet been oxidized, and its heat-clearing and detoxification effect is the strongest.

When boiling mung bean soup every day, because it takes too long to cook it, it is difficult for them to maintain their yellow-green color, but they turn red.

This is because the fruits of black grains such as black beans and black rice have natural pigments that are usually deposited in the protective film of the epidermis. When soaked, the pigment dissolves in the water, and the water changes color. If soaked in hot water, the protective film is immediately destroyed by the high temperature, and the pigment is released more quickly.

Therefore, discoloration is a normal phenomenon.

To distinguish whether the color has faded naturally or has really been dyed, you can use a few grains to scratch on the white paper when buying, and the dyed black beans will leave black marks. You can also peel off the outer skin of black beans, the inner wall of the outer skin of real black beans is white, and the dyed ones are black.

First see if the bean meat inside is green, if so, it is a real black bean, if it is yellow, it is dyed by soybeans.

Other than that; Black beans and black rice soaked in water will fade.

Normal, the instructions are fresh.

1. If the mung bean soup is black after it is boiled, you can check whether Qiaoyu is boiling in an iron pot, because mung beans are cooking in an iron pot, and the mung beans and the iron pot will react to generate some black iron tannin, so that the mung bean soup is black.

2. The cooking time is too long, because mung beans are rich in green leaf pigment, green leaf pigment is not resistant to high temperature, in the case of long-term high temperature cooking, it is easy to brown, when the cooking time is too long, it will slowly brown, and in serious cases, it will turn black.