Grifola frondosa has a unique aroma and taste, is rich in nutrition, is not only a delicacy at banquets, but also has health care and medicinal value, and is a precious edible and medicinal bacteria.

Grifola frondosa, whether dried or fresh, is loved by people. Its taste is fragrant, its meat is crisp and tender, and it tastes like shredded chicken, crisp like magnolia and delicious. There are many ways to eat, such as frying, burning, rinsing and stewing. Can make soup, stuffing, cold spell; The cold dish is crisp and tender, and the fried food is fragrant and delicious; Burning and stewing have the characteristics of "instant use, but still crisp after long cooking", and the soup has a particularly good flavor and is a rare delicacy at the banquet. Fresh Grifola frondosa is tender, crisp, smooth and refreshing, and suitable for cooking and soup. Dried Grifola frondosa is rich in fragrance and is regarded as a delicacy and a feast treasure; Canned Grifola frondosa has both color and fragrance. Grifola frondosa is characterized by high protein, low fat, complete essential amino acids (cereals generally lack 1-2 essential amino acids) and rich in vitamins. Japanese people like to rinse hot pot with fresh Grifola frondosa. Dried products still have a unique flavor after soaking, so Grifola frondosa is a good gift in Japan, and its sales volume is second only to mushrooms and Flammulina velutipes, ranking third.

Like other edible fungi, Grifola frondosa not only tastes delicious, but also has a certain health care function. Traditional Chinese medicine believes that Grifola frondosa is sweet and cool, non-toxic, and has the effects of invigorating spleen and qi and clearing away summer heat. In addition, it can lower blood pressure, enhance the body's disease resistance and accelerate wound healing. Grifola frondosa is rich in lysine and arginine, which can promote children's intellectual development, especially for pregnant and lactating women. It can promote the intellectual development of the fetus and make the baby smart and strong. Therefore, it is called "Lizi Mushroom". Grifola frondosa contains a high proportion of polysaccharides, which has the effect of improving human immunity. Therefore, Grifola frondosa is a "green" healthy food for both food and medicine, which can enhance people's physique if eaten frequently.

(1) protein and amino acids

1. protein. To evaluate the nutritional value of food, generally, we mainly make a nutritional evaluation on its protein, that is, the nutritional value depends on the content of protein in food and the quality.

the protein content is usually measured by micro kjeldahl method, and then the protein content of the sample is obtained by multiplying the nitrogen content by the protein conversion coefficient of 6.25. However, the cells of mushroom fungi also contain non-protein nitrogen-containing substances such as chitin, so the measured values are higher than the real protein content, or the data recorded in various literatures are different. In order to solve this problem, Fitzpatrick suggested using N×4.38 as the conversion formula, which can accurately express the actual content of fungal protein.

among the 1 rare edible fungi listed in table 1-1, the protein content of Grifola frondosa is 31.5%, which is second only to the most famous rare species Tricholoma (39.3%) in China, and equivalent to the high-grade species Morchella (31.4%). This shows that Grifola frondosa is a veritable mushroom species with high protein.

Table 1-1 Nutritional components (dry weight,%) of edible fungi such as Grifola frondosa

Comparatively speaking, the protein content of dried Grifola frondosa is 2-4 times higher than that of cereals, such as rice is 7.3%, wheat is 12.7%, and the protein content of dried Grifola frondosa is as high as 31.5%. Although the protein content of soybean is as high as 39.1%, its protein utilization rate is only 43%, while the protein utilization rate of Grifola frondosa is as high as 8%, mainly because the essential amino acid content in soybean is only .46%. If soybean and Grifola frondosa are eaten together, the protein utilization rate of soybean can be increased to 79% ~ 8%.

Being fresh with water, the protein content of fresh Grifola frondosa is higher than that of vegetables, meat, eggs and milk (Table 1-2), which is not only much higher than that of spinach, potatoes and tomatoes, but even higher than that of milk. Although it is not as good as meat and eggs, the fat content and calories of Grifola frondosa are much lower. Therefore, nutritionists have a high evaluation of the nutritional value of Grifola frondosa, calling it "plant meat" with high protein, low fat and low calorie.

Table 1-2 Comparison of nutritional components between fresh Grifola frondosa and other foods (%)

Note: ① The calorie is 1g of fresh food.

② A person weighing 65kg needs 6552kJ/day for basic metabolism.

2. amino acids. Amino acids are the basic units of protein, and there are two configurations: L-type and D-type. The amino acids in natural protein are all L-type. One third of the total amino acids are free amino acids, and the other two thirds are bound in protein.

there are more than 2 kinds of amino acids in natural protein. Amino acids can be divided into essential amino acids and non-essential amino acids according to whether the human body can synthesize them. Essential amino acids are amino acids that are necessary for human growth and development, but cannot be synthesized or transformed by themselves, but must be supplied through food. There are 8 kinds of essential amino acids, including lysine, leucine, isoleucine, valine, threonine, phenylalanine, methionine and tryptophan. On the contrary, nonessential amino acids refer to those amino acids that can be synthesized or transformed by the human body itself.

Grifola frondosa contains 18 amino acids, including 8 essential amino acids (Table 1-4). The amino acid content of Grifola frondosa is also higher than other foods, especially the tryptophan content of essential amino acids is higher than that of lean pork and eggs. It can be seen that Grifola frondosa contains comprehensive and balanced nutrition and belongs to the top grade among edible fungi. It is particularly worth mentioning that lysine and leucine, which are rarely contained in cereals, and tryptophan, which is rarely contained in beans, are also relatively high in Grifola frondosa. Therefore, Grifola frondosa and other foods can complement each other in nutrition, so that the intake ratio of amino acids is closer to the mode needed by the human body, thus improving the nutritional potency of food. It should be pointed out that the amino acid content of artificially cultivated Grifola frondosa is higher than that of wild Grifola frondosa, which may be due to the fact that the nutrition of artificially cultivated materials is higher than that of natural substrates.

Table 1-4 Comparison of amino acid content between Grifola frondosa and other foods per 1g (g)

Table 1-4 Comparison of amino acid content between Grifola frondosa and other foods per 1g (g) (continued) -1

Note: ① Those marked with * in the table are essential amino acids, accounting for about 4% of the total.

② Grifola frondosa was determined by the Quality Inspection Center of the Ministry of Agriculture; Others are quoted from the Food Composition Table.

(2) vitamins and minerals

1. vitamins. Vitamins do not provide heat energy to the body or participate in the composition of tissues, and the demand for vitamins is very small, but vitamins are an important substance necessary to maintain normal life activities of organisms, and their main function is to participate in the metabolism of organisms as coenzyme. The human body can only synthesize a few vitamins, and most vitamins need to be supplied by food. Grifola frondosa is rich in various vitamins, such as vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin C (ascorbic acid) and vitamin VE (Table 1-5).

table 1-5 vitamin content per 1g of dried Grifola frondosa and other edible fungi (mg)

(1) vitamin e. The proportion of vitamin E in Grifola frondosa fruiting body is very high, ranking second among 1358 foods listed in the Food Composition Table, second only to linseed oil (389.9 mg/1 g). Vitamin E can remove toxic peroxides from human body, prevent lipid peroxidation of cell membrane, inhibit the formation of chloasma and liver cell aging in middle-aged and elderly people, and has the effect of delaying the aging of the body. Middle-aged and elderly people, especially menopausal women, have good anti-aging and beauty effects. It is particularly worth mentioning that vitamin E is beneficial to human germ cells. When vitamin E is lacking, human reproductive function will decline.

(2) Vitamin B1 is also called thiamine. Its main functions are to protect the nervous system, promote individual development and participate in the catabolism of sugar in the form of coenzyme. Mild deficiency of vitamin B1 can cause fatigue, depression, impatience, loss of appetite, growth retardation, etc. If vitamin B1 is in short supply for a long time, it may lead to emaciation, edema, decreased heart function and beriberi. A recent new study shows that eating foods rich in vitamin B1 or taking vitamin B1 pills can reduce the risk of heart disease. The content of vitamin B1 in Grifola frondosa is relatively high, reaching 1.47 mg/g dry weight. An adult eating 5 grams of fresh Grifola frondosa is enough to supply the vitamins needed for one day, which is enough to prevent beriberi.

(3) vitamin C. Also known as ascorbic acid, it is the first vitamin found in citrus. Vitamin C is of great significance to human health. It can prevent scurvy. Promote human metabolism and wound healing; Improve the immunity of the body; Regulate the metabolism of fat, lipid and cholesterol; Improve teeth and bones; Strengthen the capillary wall and improve blood vessels; At the same time, vitamin C also has the function of detoxification. When toxic substances, such as lead, arsenic and benzene, enter the body, vitamin C will combine with them to form anti-bad blood cells and be excreted with urine. In addition, vitamin C can prevent the formation of nitrite in the body. The carcinogen ammonium nitrite is produced by the combination of nitrite and amine. Without nitrite, ammonium nitrite cannot be formed, which has a good effect on preventing cancer. Lack of vitamin C can lead to scurvy, mainly manifested as swelling and loosening of teeth, capillary bleeding and other symptoms. American nutritionists Barra and Katz also found that people's IQ is indirectly related to the content of vitamin C in blood. The blood vessels that transport nutrients in human brain cells will be blocked and thinned due to the lack of vitamin C, resulting in decreased brain function. Grifola frondosa is rich in vitamin C, with 17 mg per 1 g of dried Grifola frondosa.

2. minerals. The chemical substances left in ash after burning of Grifola frondosa fruiting body tissue include potassium, phosphorus, sulfur, sodium, calcium, magnesium and trace elements such as copper, iron, manganese, molybdenum and cadmium. Minerals can make bone structure have certain strength and hardness, activate enzyme system, control body fluid balance and adjust acid-base balance, and also play a special role in muscle and nerve stress. Mineral deficiency can cause a series of diseases of human body, such as potassium deficiency can cause rapid heartbeat, arrhythmia, muscle weakness, diarrhea, abdominal swelling and so on; Calcium deficiency can cause osteomalacia and osteoporosis, and the elderly are prone to dementia, while children's calcium deficiency will seriously affect their growth and development. Phosphorus deficiency can cause weakness, loss of appetite, muscle weakness, bone pain, etc. Iron deficiency can cause iron deficiency anemia and so on.

Both wild Grifola frondosa and cultivated Grifola frondosa contain many minerals beneficial to human body, such as potassium, phosphorus, sulfur, magnesium, calcium, iron, sodium, zinc, copper, manganese, boron, chromium and selenium (Table 1-6).

table 1-6 mineral content (mg) per 1g of wild Grifola frondosa and cultivated Grifola frondosa

Organic chromium in Grifola frondosa can coordinate with insulin, maintain normal glucose tolerance, and has effects on liver cirrhosis and diabetes.

Trace element selenium (Se) is a chemical element between metal and nonmetal, and only one hundredth of it exists in some sulfide ores in nature, which is a rare element.

In p>1817, Swedish chemist Breezing discovered selenium in the residue left over from sulfuric acid production, and it was not until 1957 that selenium was found as a protective factor to prevent nutritional liver necrosis. In 1973, the United Nations Health Organization declared: "Selenium is an essential trace element in animal life". Then, Chinese medical household selenium has made remarkable achievements in preventing and treating endemic diseases such as Keshan disease and Kaschin-Beck disease, and won the highest honor award of the World Trace Element Research Center-Schwartz Prize in 1984. Later, after a lot of research, Chinese scientists proved that selenium has preventive and therapeutic effects on cancer, cardiovascular and cerebrovascular diseases, liver and kidney diseases, diabetes, hemolytic anemia, asthma, arthritis, cataracts and stunted children. And selenium can antagonize, detoxify and excrete toxic substances such as cadmium, mercury, arsenic and lead in human body. China has always been in the leading position in the international research on the relationship between selenium and human health. In October 1988, the Nutrition Society of China listed selenium as one of the 15 essential nutrients for human life, and stipulated that the daily intake of selenium for each person was 15 micrograms for infants from birth to 12 months, 2 micrograms for children aged 1-3 years, 4 micrograms for children aged 4-6 years, and 5 micrograms for children over 7 years old (teenagers, youths, adults and the elderly).

There are more than 4 countries and regions in the world that lack selenium, and the situation of selenium deficiency in China is more serious. In 198, 312,278 grass and soil samples were collected and measured in 1,94 counties (accounting for about half of the country) in 3 provinces, municipalities and autonomous regions (except Taiwan Province Province), and it was found that selenium was seriously deficient (the selenium content was ≤.2 mg/). There are 474 counties in selenium-deficient areas with selenium content of .3 ~ .5 mg/kg, accounting for 43% of the total; There are 27 counties with selenium content of .6 ~ .9 mg/kg, accounting for 19% of the total; Only 12 counties are normal (≥.1 mg/kg), accounting for 9% of the total. It can be seen that 72% of counties in China are deficient in selenium (one third of them are seriously deficient in selenium), which will inevitably lead to the production of a large number of low-selenium grains and vegetables, resulting in a low-selenium food chain, resulting in a low selenium ratio in food sources for people and livestock, which will affect the health of people and animals. Selenium must be supplemented in these areas, otherwise the local people are prone to selenium deficiency diseases, such as hair loss and hemolytic anemia. Therefore, it is necessary to study and develop the social significance of selenium-enriched food.

In recent years, studies at home and abroad have found that many edible fungi, such as Grifola frondosa, Lentinus edodes, Pleurotus ostreatus and Grifola frondosa, have selenium-enriched ability. The selenium content of Grifola frondosa cultivated naturally is only .1 mg/kg dry product, but it can be artificially increased by using the selenium-enriched ability of Grifola frondosa mycelium. The experiment of Liang Ying et al. (2) showed that the selenium content of Lentinus edodes could be increased by 129.81 mg/kg dry product by applying selenium in the culture medium, which was more than 3 times higher than that of the control (.42 mg). The absorption rate of organic selenium contained in edible fungi by human body is as high as 97.5%, which is an excellent selenium supplement food. For example, the selenium content of Grifola frondosa cultivated with selenium can reach 1 mg per kilogram of dried products. According to the minimum selenium requirement standard of human body over 7 years old determined by China in 1998, the selenium content of 1 kg of dried products with selenium content (1 micrograms) can be eaten by one person for 2 days, and 5 grams per day can meet the national health standards.