Can the white lotus root turn purple-black and can still be eaten? Expert: You can eat it without decay

Wuhan Evening News, October 17 (reporter Chen Qixiong intern Xia Gu) white lotus root bought from the market or supermarket, after a few hours at home, it became purple-black. On October 17, Mr. Zheng, a citizen, called the Yangtze River Daily news hotline and asked why the lotus root changed color? Has it been soaked in chemical potions? Can I still eat it?

Mr. Zheng, 75, lives in hankou sister-in-law tree green home community. He said that he and his wife like to eat lotus roots, and especially love to use lotus roots to simmer soup. In the past, most of the lotus roots sold by vegetable vendors in the wet market were still sticky to the mud. Most of the lotus roots sold by the greengrocers have now been washed. A few days ago, he went to the YangfenHu Vegetable Market and bought a few pounds of lotus roots to go home, which were white and fat. A few hours later, when they wanted to use these lotus roots to cook, they accidentally saw that the lotus roots had all turned purple-black. They suspected that the lotus roots might have been soaked in potion, so they went to the vegetable market to ask the vegetable vendors for explanations, but the vegetable vendor said that the lotus roots changed color normally.

Mr. Zheng said that he and his wife would be suspicious of what the greengrocer said. On the morning of October 16, he and his wife went to a supermarket in Xinhua Homestead to buy lotus roots. By the afternoon, the lotus roots had turned purple-black. When they carried these lotus roots to the supermarket salesman theory, the salesman also insisted that there was no quality problem with the lotus root, but he could not say why. Finally, the supermarket clerk agreed to return them.

Is it normal for lotus roots to change color? To this end, the reporter interviewed Mr. Dong Likun, a plant expert at the Wuhan Academy of Landscape Sciences.

Dong Likun said that the reason why lotus root changes color is because of the presence of polyphenol compounds and polyphenol oxidase and other substances in lotus root. When lotus root is exposed to air for a long time, polyphenolic compounds, catalyzed by polyphenol oxidase, produce tan quinones. Quinones are then automatically polymerized to form a dark-colored substance. As a result, the lotus root changed color. Lotus roots that have changed color can still be eaten with confidence as long as they do not rot.

Mr. Dong Likun said that it is not difficult to keep the lotus root white. First, before cooking, you can soak the lotus root with vinegar or citric acid. Both vinegar and citric acid can inhibit the activity of polyphenol oxidase, thereby preventing lotus root from changing color. The second is to put the lotus root in boiling water at 100 ° C and blanch it for about 70 seconds, which can also inactivate the polyphenol oxidase and prevent the lotus root from changing color. The third is to cover the lotus root that is temporarily uneaten with plastic wrap and isolate it from the air, which can prevent it from changing color.

Edited by Zhao Ke