"Phenoloxidase" naturally exists in fruits, vegetables and potatoes, and it is also rich in "polyphenols" with antioxidant effect. If they meet together and add oxygen, enzymatic browning will occur, that is, phenol oxidase catalyzes the oxidation of colorless polyphenols to produce colored "quinones" These quinones can polymerize with each other to make the color darker and darker. Although no harmful substances are produced in this process, the antioxidant capacity of polyphenols decreases and vitamin C is also lost after browning. In order to avoid this reaction, the raw materials should be scalded with boiling water before juicing to inactivate phenol oxidase, or a piece of vitamin C should be added when juicing. If potatoes, lotus root slices or yam can't be cooked immediately after being cut, they should be put into water dripping with vinegar.
The potato turns black after peeling because the inside of the potato reacts with oxygen and changes its original color. It usually only happens on the surface. The surface of the potato can be peeled off. If the color doesn't change, you can eat it. If it turns black inside, you can't eat it.
Potato storage method:
Potatoes can be preserved in clean water after peeling, which can ensure that potatoes do not react with oxygen and filter out excess starch.
Can potatoes be eaten after peeling and turning black? Potatoes can be eaten after peeling and blackening.
1. Potatoes contain a substance called cyanine. Directly exposed to the air after peeling will be oxidized by oxygen and turn black.
2. Potato seeds contain an organic compound tannic acid, which will react with heavy metal knives and steel balls to produce ferric tannic acid or tannic acid salt, thus turning black.
3. After peeling, wrap it in plastic wrap and put it in the refrigerator, or soak it in water, which can be stored for 1-2 days.
4. Putting peeled potatoes into water and adding a few spoonfuls of salt can effectively prevent potatoes from turning black and prolong the storage time of potatoes.
5. Peeling potatoes, putting them into water and adding a few drops of vinegar can reduce the activity of enzymes in potatoes and prolong the storage time.
Why do potatoes turn white at first and then turn black gradually? Can such potatoes be eaten? How to distinguish this kind of potato from ordinary potatoes? Starch in potatoes is oxidized in the air.
Can potatoes be eaten without peeling? Potatoes that have not germinated and turned green are naturally the safest if they can be thinned. Potatoes that are not peeled will not be poisoned if you don't eat too much. If you eat potatoes that sprout and turn green, you will be in considerable danger of poisoning. So I thought, to be on the safe side, I'd better peel it off before eating.
What is the reason why potatoes peel and smell like garlic? Can such potatoes still be eaten? Potatoes with buds cannot be eaten. Garlic-flavored potatoes have begun to sprout in it.
Will eating potatoes turn black? It's okay. Misleading. As early as 1997, China Nutrition Society called on residents to "eat more vegetables, fruits and potatoes". Nowadays, vegetables and fruits have attracted people's attention, but potatoes are often forgotten. In particular, many people have always mistakenly thought that potato starch content is too high, which is a food that is easy to cause obesity, so they are discouraged from potatoes. In fact, from the perspective of staple food, the starch content of potatoes is not high, and it can also help people lose weight. This is because potatoes have high water content, starch content is only about 20%, and they are also rich in soft dietary fiber that can produce satiety. Therefore, if potatoes are used instead of white rice and steamed bread, even if you let go of your stomach, it is difficult to make people obese. What needs to be known now is that, as a part of staple food, the content of potassium and magnesium in potatoes is higher than that in polished white rice and polished white flour, which is an alkaline food and is conducive to maintaining the acid-base balance in the human body. Secondly, the protein of potatoes is of high quality and rich in lysine, which enables people to obtain various amino acids needed by the body. Third, potatoes contain vitamin C, which is a good thing that polished rice and white flour do not have. Fourth, potatoes contain dietary fiber, which is soft and will not affect the stomach. People with gastric ulcer or enteritis can also rest assured to eat potatoes. It should be noted that because potatoes absorb fat easily, if oil is added when cooking potatoes, other foods rich in fat will be cut.
How long can potatoes be preserved after peeling? How to peel potatoes and soak them in water, but they can't be stored for too long. Generally, there are more in one day. Potatoes are prone to oxidation.
Putting potatoes in water is a soaking method. The peeled potatoes are soaked in cold water to isolate the oxygen in the air, so that they will not change color.
The activity of phenol oxidase measured by acid addition method is the strongest when the PH value is 6-7, and it will decrease when the PH value is less than 3. Therefore, adding vinegar to food to reduce the PH value can inhibit the activity of enzymes and slow down the speed of discoloration. This method has a slow storage effect.
This situation is not uncommon in real life, such as apples, eggplant, lotus roots and so on. After peeling, enzyme browning will lead to darker color, and it will not change color if it is immersed in cold water to isolate oxygen in the air. There is no problem if you eat it, but the color will not look good after cooking, which will affect your appetite. You can peel it again.
Can germinated potatoes be peeled and eaten? Hello, germinated potatoes contain an alkaloid called solanine, which has a * * * effect on gastrointestinal mucosa, hemolysis and paralysis of respiratory center. Germinated potatoes have a high content of eye buds, root buds and green parts, and people will have symptoms such as itchy throat, nausea, vomiting, abdominal pain and even death, so germinated potatoes cannot be eaten. You ate it, because you peeled it and removed some toxins, and you cooked the potatoes thoroughly, and the solanine dissolved.
Guiding opinions:
I suggest you don't eat these sprouted potatoes in the future, because it's easy to forget to peel them when eating, and it's easy to be poisoned. Wish you good health.