Why does the latest lotus root turn black?

Lotus root is also known as lotus root, Rong Yujie, jade exquisite, growing under water, rich in nutritional value, often eating lotus root can improve our immunity, but also play the effect of reducing fire, is one of the vegetables that many people like to eat. However, people often encounter the phenomenon that the lotus root blackens in their daily life. If the lotus root bought is not eaten in time and placed for a period of time, it will be found that it has turned black, so what is the reason for the blackening of the lotus root? Then today we will take you to understand the causes of the blackening of the lotus root and the solutions!

First, the reason why the lotus root turns black

In fact, the blackening of lotus roots in iron pots has something to do with the polyphenols contained in them. A common property of these guys is that they can combine with iron ions to form colored complexes of purple or blue. One of the rich polyphenols in lotus root, Gallic acid combines with iron ions to form a blue-black substance, which is the main component of blue-black ink. No wonder the chop soup can be turned into ink soup.

The secret of stewing lotus root into ink in an iron pot is found, but why do the lotus roots that are put in the basket without any contact with iron turn black? This is because the polyphenols in the lotus root mentioned above are oxidized to chemicals called quinones under the action of polyphenol oxidase (PPO), which are polymerized together to form melanin. In fact, it is all for this reason that the cut apples turn brown and the bananas in the refrigerator turn black.

Second, the solution to the blackening of lotus root

In fact, it is not difficult to keep the lotus root white. Blanching in 100 ℃ boiling water for 70 seconds can disable all polyphenoloxidase, which stops the conversion of polyphenols to quinones. However, I'm afraid this method is only suitable for stewed lotus root ribs and other dishes that require a soft waxy taste. If you make cold lotus root slices in this way, the black is not black, but it also loses its crisp taste.

Don't worry, in addition to high temperature treatment, the proper addition of acid can also bind the hands and feet of polyphenol oxidase. When making cold lotus root slices, adding vinegar to the scalded lotus root slices can largely avoid the catalysis of polyphenoloxidase and keep the lotus root white. In fact, citric acid and other substances that inhibit the activity of polyphenol oxidase are added to some ready-to-eat packaged lotus root slices.

Those bought back fresh lotus root, can not be eaten in a short period of time, and how to keep white? This is not difficult, although polyphenol oxidase has a strong catalytic effect, but with the participation of oxygen, the phenols in lotus root can be oxidized to quinone, so isolating oxygen is also a method. Soaking the lotus root in water can delay the process of blackening the lotus root.

We have learned that there are many lotus root practices, such as cold salad, stir-fried stew, gravy and other lotus root enjoy the reputation of the king of ingredients, because it has many cooking methods, but also can be matched with different cuisines. In fact, there are many little mysteries in life that we don't know. As long as we find them with our heart, we will get something. I believe everyone knows something about the treatment of lotus root, right?