The method of yam not blackening:
First, don't use metal props (stainless steel can) to cut yam. Use wooden knives or knives made of materials.
Second, the cut yam is soaked in salt water or cold water with vinegar, or it can be soaked in lemonade, and then simmered when frying yam.
Extended data
The secret of peeling yam: cut it in water with gloves on.
Yam is delicious and nourishing, but it has one disadvantage: it is easy to be allergic when your hands touch mucus. This is because the mucus secreted by yam contains plant alkaloids and saponins, which is very irritating and itchy when it comes into contact with the skin. Washing with water won't help. When peeling yam, if you touch your hand, it will be very uncomfortable for a while.
At this time, you can wear plastic or disposable gloves and peel yam in water, which can not only prevent mucus from sticking to your hands, but also prevent yam from slipping in your hands.
People's Daily Online: What should I do if yam turns black? How can we keep yam from discoloring?