The main components of Dioscorea opposita Thunb. It is composed of starch 16% (amylase), protein (glycoprotein including 16 amino acids), sugar (mannose, glucose, galactose), saponin mucus, vitamins, iron and manganese, etc. It is characterized by straight, white color and foot powder.

Iron stick yam is a variety of yam produced in wen county, which belongs to the "best" of Huai yam. Its main components are saponin, mucus, choline, diosgenin, starch, glycoprotein, free amino acids, polyphenol oxidase, vitamin C, iodine, 16 amino acids and various trace elements such as iron, copper, zinc, manganese and calcium. Has the effects of invigorating spleen and lung, strengthening kidney and brain, improving intelligence and caring skin, resisting aging, resisting tumor, relieving fatigue, resisting the stimulation of harmful substances, regulating metabolism, enhancing immune function, promoting growth, regulating endocrine, regulating renal function, exciting hematopoietic system and regulating nervous system. It is the most valuable and nourishing variety in traditional Chinese medicine.

Regular consumption can not only strengthen the body, maintain beauty and delay aging, but also have a good effect on lumbago due to kidney deficiency, dysmenorrhea, deficiency of kidney essence, loss of appetite, eating less sugar, diarrhea due to spleen deficiency, chronic cough due to lung deficiency and obesity.

Second, the medicinal value:

Yam is sweet and flat in nature, and belongs to spleen, lung and kidney meridians. It is an important tonic medicine, which has the effects of nourishing kidney, invigorating stomach, resolving phlegm, invigorating middle warmer, invigorating qi, expelling wind and dispelling cold, calming the heart and calming the nerves, strengthening tendons and promoting marrow production.

Clinically, it is often used for anorexia due to spleen deficiency, chronic diarrhea, asthma and cough due to lung deficiency, nocturnal emission due to kidney deficiency, increased leucorrhea, frequent micturition, deficiency heat to quench thirst, neurasthenia and other symptoms. Raw yam is often used for chilblain of hands and feet, excessive phlegm, asthma, frequent urination and other diseases, and is one of the commonly used tonics in Chinese medicine prescriptions. The processed yam is called Guangdong yam. Before yam is used as medicine, it should be soaked in clean water for 30-40%, taken out and fully moistened, dried to 40%, moistened evenly inside and outside, sliced and dried for medicine. ?

Third, the characteristics:

Yam, also known as Dioscorea opposita, is a sweet potato. Its root is used as medicine, because its efficacy can be compared with ginseng, so it is also called "Huaishen". It is a perennial twining herb with fleshy roots, slightly columnar and different lengths. Yam is a precious medicinal material, which has the functions of invigorating spleen and stomach, nourishing liver and kidney. There are many producing areas of yam in China, but the yam in Jiaozuo, Henan Province is the best. Jiaozuo was called Huaiqing House in ancient times, so the yam here is also called yam. Chinese yam. It has always been evaluated by doctors as "warming and nourishing" and "balancing nature", which is a model of "homology of medicine and food" and can be used as normal food to satisfy hunger, and users have no taboos. ?

Extended data

(1) yam

Dioscorea opposita is a specialty of Jiaozuo City, Henan Province, and a symbolic product of China's national geography. ?

During the Qin and Han Dynasties, Shennong's Classic of Materia Medica recorded that Huaiqing in Henan was the best yam. Jiaozuo was called Huaiqing House in ancient times, with Taihang Mountain in the north and Yellow River in the south. Its natural conditions are unique, and yam, rehmannia, chrysanthemum and Achyranthes bidentata are well-known at home and abroad. Dioscorea opposita is the first of the "four Huai drugs", and doctors evaluate its "warming and nourishing" and "flat nature", which is a model of "homology of medicine and food". "Iron stick yam" is a treasure in Huai yam. It is named because of its reddish brown color, solid powder, thin body and long body, and its appearance resembles an iron bar. The main producing area is Wenxian County.

(2) Screening and selection

1, look at the diameter

Iron stick yam is uniform in thickness, with a diameter of 1-2 cm (like an adult's thumb), slightly dark in skin and iron red spots on the root; If the diameter is too thick or the skin is too smooth, it means it is not authentic.

Step 2 look at rust

When the iron stick yam is broken, it can be felt that its meat is hard, full of powder, delicate cross-section, white or yellowish, and less mucus; Ordinary yam is not only not so hard, but also not enough powder.

Step 3 have a taste

Because the iron stick yam contains less water, is rich in yam polysaccharide, and its juice is thick. After cooking, it tastes dry, greasy and sweet, with a "sweet with sweet" feeling at the entrance, accompanied by a faint hemp taste.

4. 10% discount

When the iron stick yam is broken, it can be felt that its meat is hard, full of powder, delicate cross-section, white or yellowish, and less mucus; Ordinary yam is not only not so hard, but also not enough powder. ?

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