1. Dried mushrooms can be soaked in warm water at 30℃ for about an hour. You can't use hot water when soaking, otherwise the nutrients in the mushrooms will be lost, the taste will be reduced, and you can't soak them for too long, especially in summer when the temperature is high, which will breed a lot of bacteria and microorganisms and lead to the deterioration of mushrooms.

2. The nutritional value of Lentinus edodes:

(1) Lentinus edodes is known as a delicious food, which was recorded as a tribute in the Song Dynasty, and it is also an indispensable vegetarian dish in China folk banquets. The Japanese called mushrooms the pinnacle of plant food, and the Romans listed them as sacred food. Mushrooms are rich in nutrition and are very beneficial to human health.

(2) According to the analysis of food experts, the edible parts of dried mushrooms account for 72% of the whole, and each 100g edible part contains 13g water, 1.8g fat, 54g carbohydrate, 7.8g crude fiber, 4.9g ash, 124mg calcium and 465433.

(3) Lentinus edodes also contains more ergosterol and mannitol, which can be converted into vitamin D2 by sunlight or ultraviolet irradiation, which can enhance human immunity and contribute to the growth of children's bones and teeth. It is reported that Lentinus edodes contains more than 30 kinds of enzymes, which is a unique food to correct the lack of enzymes in human body.

(4) Every 100g fresh mushroom has 40 calories, which can provide 3.4g protein. Compared with other fruits, vegetables and plant foods, mushrooms are high-protein and low-calorie foods. Lentinus edodes contains lentinan and ribonucleic acid, which can "activate T cells, macrophages and complement system" and "enhance the ability of human body to inhibit the growth of cancer cells". Therefore, regular consumption in the diet has a certain effect on cancer prevention.

(5) Lentinus edodes contained in Lentinus edodes can also reduce cholesterol and provide good protection for cardiovascular system. Mushrooms contain ergosterol, which is the precursor of vitamin D and can be converted into vitamin D under sunlight or ultraviolet irradiation. Therefore, it is impossible to get vitamin D by eating artificially heated dried mushrooms.