Why do beans turn black after being dried? How can beans be dried green?

I don’t know if you have noticed that beans will turn yellow or black after being dried. This is actually a very common phenomenon. If you want to prevent the beans from changing color after drying, you need certain skills. You must take good care of them from the beginning to the drying process. For details, you can see the tips on how to make the beans green when dried provided on this site.

Why do beans turn black after being dried?

As a result of oxidation, when the beans are cooked, the chlorophyll discolors and turns yellow, and then turns red and black when dried.

Those who have experience in drying beans will blanch the fresh beans in boiling water for a few minutes before drying. This is mainly to prevent enzymatic browning. When the bean tissues and cells are damaged, oxygen enters, and phenolic substances undergo a series of oxidation and polymerization reactions under the action of phenolase to form brown pigment. Enzymatic browning requires three major elements: phenolic substances, enzymes, and oxygen. Plant tissues themselves contain phenolic substances, which will inevitably come into contact with oxygen during the drying process. Therefore, if we want to prevent enzymatic browning of beans, the best way is to control the activity of the enzyme, and the easiest way to achieve this at home is blanching.

How to make dried beans green

I dry beans every year, but I don't specifically ask for the color of the beans. Because most home-dried beans are exposed to the sun first, so the beans will definitely change color. But I have a practical tip:

1. After the water is boiled, you can add a little alkali (too much will destroy the vitamins), put the beans into the pot and blanch them. As soon as they turn green, take them out and rinse them with cold water. This will ensure that the beans are emerald green when they come out of the pot.

2. Drain the beans and place them directly on a drying rack to dry in the shade. Place a dehumidifier under the rack and blow the air toward the beans. (In the summer, you can use a dehumidifier at home, which is a good way to kill two birds with one stone.) This way, the beans can maintain their green color after being dehydrated.

Friendly reminder: If conditions permit, you can use a dryer to dehydrate the beans directly. If you don’t have drying equipment, you really don’t need to care about the color of the beans. Exposure to the sun has a sterilization effect and helps to dry them, and the taste remains the same.

How to make roast pork with dried beans

Main ingredients: dried beans, pork belly.

Seasoning: salt, light soy sauce, dark soy sauce, cooking wine, sesame oil, sugar, onion, ginger, garlic, shallot, oil, pepper, aniseed, soup stock.

step:

Step 1. Soak the dried beans in water for two hours until soft. Cut into sections. Cut the pork belly into strips. Slice the green onions, ginger, and garlic. Cut the chives into chopped green onions.

Step 2. Heat oil in a pan. Add pork. Stir-fry until oil comes out. Add pepper, aniseed, onion, ginger, garlic. Stir-fry until fragrant. Add a little cooking wine. Add dried beans. Stir-fry evenly. Add a little broth and a little sugar.

Step 3: Add a little sesame oil and sprinkle with some chopped green onions before serving.