How can I prevent yam from turning black

Yam is a very common thing in our daily life, and it is rich in nutrients. Although yam is delicious and has the function of nourishing the body, people who have handled yam know that the mucus of yam can cause allergies. This kind of allergy is unbearable. Moreover, after peeling, some yams will turn black. So how can yam not turn black? Here is how to prevent yam from turning black.

Why does yam turn black?

1. Oxidation after being placed in the air for a long time

Yam contains a certain amount of polyphenols and polyphenol oxidase. After being cut and exposed to oxygen in the air, the activity of the enzyme increases, and the polyphenols will be oxidized into quinones, which will easily turn black. This is the same as apples, eggplants, potatoes, etc., which change color over time after being cut.

2. Or it may be caused by frying in an iron pan

People who often eat yam should know that yam, like lotus root, is a calcium starch food. This kind of food is not suitable for cooking in an iron pan. In addition, the phenolic substances in the yam will react with iron ions to produce a dark blue or black complex, causing the yam to turn black.

Can I still eat yam if it turns black?

The phenolic substances in yam, whether they are quinones generated by oxidation or complexes generated by reaction with iron ions, are not toxic, and both substances can be digested, so they can be eaten safely and are harmless to the body.

However, yam that turns black when used in cooking will not look very attractive and most people will lose their appetite, so it is crucial to learn how to cook yam without it turning black.

How to make yam without turning black

1. Soak in clean water after cutting

Soak the yam in clean water as soon as possible after peeling or cutting.

2. Soak in vinegar, salt, etc. after peeling

In addition to soaking in water after peeling or cutting the yam, it is best to add a certain amount of vinegar, salt, etc. to the water, which can more effectively prevent the yam from oxidizing and turning black.

3. Use a casserole to cook yam

It is best to use a casserole when cooking yam. When cooking in an iron pan, some iron ions will dissolve in the soup, which will react with the phenolic substances in the yam and turn it black. A casserole can completely avoid this phenomenon.

4. Blanch with boiling water after cutting

The phenol oxidase contained in yam has a certain activity. Therefore, blanching the cut yam with boiling water can inactivate the enzyme on its surface and prevent it from turning black.

5. Quick peeling

There are many whiskers on the skinned yam, which will slow down the peeling process. First, put the yam on the fire and quickly burn off the whiskers. This will make peeling faster and reduce the time it is in contact with air.

6. No need to cut with a knife

The yam will change color when it comes into contact with the blade of a metal knife. You can use a bamboo knife or a plastic blade to cut it instead, or use a spoon to cut a circle on the surface of the yam and then break it with your hands.

7. Heat before peeling

To prevent the yam from changing color after coming into contact with the iron pan, put the yam with skin in a steamer or microwave and heat it for one minute. This will inactivate the polyphenol oxidase and prevent it from turning black.