1, before cooking, it is suggested that the pedicle of the towel gourd be dug (slightly deeper) to avoid the phenomenon that the towel gourd is easy to turn black after heating.

2. The purchased loofah can't be stored for too long, and it should be eaten after a day or two, otherwise it will turn black easily.

3. Wash the loofah first, then peel it. Don't wash it after peeling it, and fry it immediately.

4, cooking loofah should be lubricated, and then the soup in the pot should be adjusted first. Finally, put the loofah and mix well to quickly put it out of the pot. The loofah is not easy to turn black.

5. After the towel gourd is cut, marinate it with salt for 10 minute, and then rinse it with clear water before frying, so that the fried towel gourd will not be blackened, and the color will be more perfect.

6. The blackening of fried loofah is also related to the salt release sooner or later. Wait until the loofah is thoroughly fried, and then put salt before cooking, so that the fried loofah is not easy to blacken.

Soybean does not change color.

1, open the lid to cook. Because edamame is not easy to cook, everyone usually covers the lid when cooking edamame, so that edamame will cook faster if the hot air cannot be emitted. However, this will make edamame undergo oxidation reaction during cooking, and the appearance color will gradually become darker. The solution is to open the lid and cook edamame when cooking edamame, so that the oxidized components will evaporate with water vapor and the edamame will not change color. 2. When boiling water to cook edamame, many people like to put edamame, clear water, star anise and other seasonings into the pot to cook, but the edamame cooked in this way is easy to turn black. The correct way is that we need to boil the water in the pot first, and then pour the washed edamame into the pot to cook, so as to avoid the blackening of edamame. 3. Boil with oil. Generally, when we cook edamame at home, we only start to pour oil into the pot when we fry edamame. In fact, if we add a proper amount of oil when we cook edamame at the beginning, we can prevent edamame from turning yellow and black, and we can also make the boiled edamame bright, green and shiny.