Why do black beans turn black when soaked in water?

This is normal. It's not that the dyed color fades. Normal black beans are soaked in water, and the water also turns black. Because there is natural melanin. Do not soak for more than 1 hour to prevent nutrient loss.

However, it is necessary to pay attention to distinguish whether the black beans are dyed or not, because the dyed black beans will also fade, and there are three ways to identify black beans: one is to look at the appearance, there are "small white dots" in the middle of the real black beans, and the "small white dots" of the dyed black beans will be dyed color; The second is to look at the bean coat, the real black bean is white inside the bean coat, because the bean coat is very thin, the color of the dyed black bean will penetrate the inner skin, and after the black coat is peeled off, you can see that the inside of the black coat will also change color; the third is to rub the epidermis; Real black beans do not fade on the white paper when they are forced, and the color of the dyed black beans will leave color on the white paper after rubbing.

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Hello, because there is an oxidation, and then there is a chemical reaction, after the black spike skin of the black bean falls off, the inside is green, and then there is a black bean soak for a long time, and the outer side of my melanin is soaked off, revealing the green inlay inside, so it becomes green, which is an abnormal phenomenon, and it is also a chemical reaction. 

1. It is normal for the water soaked in black beans to turn black.

2. The color of the beans soaked in water will appear to fade the phenomenon of hail, black bean skin contains natural pigments, soaked in water for a long time will fade, black beans after a period of time, or the black beans that have been sunburned in the air, the pigment in the cells will seep out of the lead reed in the water.

3. If you buy fresh black beans, the situation of soaking water and fading will not be so serious, and if you buy old black beans, this phenomenon will be more serious.

Some people soak the black beans overnight, and the next day the black beans are washed away with lead, all faded, and the water becomes like ink. Many people think they have bought fake black beans. Is it normal for black beans to be soaked in water? What color is black bean soaking in water? Do black beans fade when soaked in water?

Is it normal for black beans to be soaked in water?

If the black bean soaking water is black, it is not necessarily a fake, but it may be. It depends.

Generally speaking, it is normal for black beans soaked in hot water to be black, and the fruits of black grains such as black beans and black rice have natural pigments, which 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.

However, if the faded color is very dark, like ink, then the black beans may have problems with dyeing.

Black beans are not black beans, authentic black beans should have a little bit of red in them, but they look black overall, black beans are often not processed by the acquired environment, they have not been polished, and fake black beans are usually very black, because they have been artificially processed, and their size is relatively uniform.

You can also put the black beans in the white vinegar for full stirring, if the white vinegar turns red after a while, then, at this time, it means that the black beans are real black beans, if the vinegar does not change any color, it is a fake black bean, mainly because the black beans have some anthocyanins on it, and in the process of mixing with the white vinegar, some chemical reactions will occur, so some pigment changes will occur.

How to distinguish a real black bean from a fake.

One is to look at the appearance. True black beans have "small white dots" in the middle. The "little white dots" of the dyed black beans will be dyed.

The second is to look at the bean coat. The inside of the real black bean is white when peeled off. Because the bean coat is very thin, the color of the dyed black beans will penetrate the inner skin, and after peeling off the black clothes, you can see that the inside of the black clothes will also change color.

If you use a dry dye, it is easy to fade, and if you use a wet dye, the skin of the bean is easy to shrink after coloring, and it is easy to be recognized.

the third is to rub the epidermis; Real black beans do not fade on the white paper. The color of dyed black beans will leave color on the white paper after rubbing.

1. The nutrients of black beans: We all know that black beans are supplements, so what nutrients do black beans contain? First of all, black beans are rich in protein, fatty acids, phosphoesters, calcium, phosphorus, iron, potassium, sodium, carotene, vitamins B1, B2, B12, E, niacin, folic acid, raffinose, stachyose, choline, soy flavonoids, saponins and many other nutrients.

With so many nutrients, does black bean water also contain so many nutrients? Let's take a look at the nutritional composition of black bean skin.

2. Nutrients in black bean skin: According to Korean scholar Lee, after research and analysis, black bean skin contains anthocyanins, hepcidins, catechins, levulin, marigoldin, quercetin, phloretin, and a variety of sugars. In other words, the water in which the black beans have been soaked is equal to the reaction of these substances with the water.

3. What are the ingredients in the black bean water: The water that has been soaked in black beans still contains the nutrients contained in black beans and black bean skin, but it is just diluted. The nutritional value provided by them has a variety of health care effects such as antioxidant activity, inhibition of mutagenesis, anti-inflammatory, cancer prevention, anti-aging, beauty and beauty, and nourishment of yin and blood.

4. From the above conclusions, black bean water contains a lot of nutrients, but it cannot be drunk raw, and it must be boiled. Many friends feel that it is not clean, you can wash the black beans before soaking the black beans, but the time to soak the black beans should not be too long, because of the temperature, the water will become stinky after a long time, and such water cannot be used.

The water in which the black beans are boiled is black.

The silvery skin of black beans contains pigments, and after a long period of soaking, the pigments are soluble in water, so the color of the soup made with black beans is black. All colored beans will fade when soaked, but compared with black beans and black rice, the pigment color of mung beans, soybeans, red beans, etc. is relatively light, and it is difficult to see with the naked eye after being diluted with water.

The nutritional values of black beans are:

1. It is of great significance to meet the human body's need for protein.

2. It mainly contains unsaturated fatty acids, which not only meet the needs of the human body for fat, but also have the effect of reducing blood cholesterol.

3. Black beans are rich in vitamins, egg yolk, melanin and lecithin, among which B vitamins and vitamin E are very high, which have nutritional and health effects.

4. Black beans are also rich in trace elements, which are essential for maintaining the integrity of the body's functions, delaying the aging of the body, reducing blood viscosity, and meeting the brain's demand for trace substances.