thin yam can be cooked in about 3 to 5 minutes after boiling, while thick yam needs to be cooked in about 8 to 1 minutes, and for yam segments, it can be cooked in about 15 minutes.

Generally, when cooking yam, the vegetable yam becomes transparent, and the iron yam becomes soft, which means it is ripe.

Chinese yam has the following functions:

1. Traditional Chinese medicines for lowering blood pressure, such as Liuwei Dihuang Pill, Bawei Dihuang Pill and Guishao Dihuang Pill, are all famous prescriptions made of Chinese yam, which are not only used to treat kidney deficiency, but also used to treat hypertension, diabetes, asthma, neurasthenia and low back pain.

2. Modern science has proved that yam can significantly reduce the activity of enzymes that accelerate the aging of organisms. Bawei Dihuang Pill containing yam is mainly used for treating postpartum sweating. Baoyuan Qingjiang Decoction and Baoyuan Hanjiang Decoction can treat hematemesis and nosebleed; Cold drenching soup and ointment drenching soup can cure drenching insects. Yam can also cure tuberculosis, typhoid fever and gynecological diseases, which are beneficial to prolonging life.

3. Anti-tumor effect Yam tuber is rich in polysaccharide, which can stimulate and regulate human immune system. Therefore, it is often used as a health care drug to enhance immunity. Dioscorea opposita polysaccharide can antagonize the cellular immune suppression caused by cyclophosphamide, and can restore some or all of the suppressed cellular immune function to normal. Yam can also enhance the phagocytosis of white blood cells.

For example, Liuwei Dihuang Pill can treat chronic nephritis, hypertension, diabetes, neurasthenia and other diseases. Zhibai Dihuang Pill can treat ankylosing spondylitis, gynecological fetal leakage, pruritus vulvae, amenorrhea and other symptoms of yin deficiency and excessive fire. Guishao Dihuang Pill can treat earache, tinnitus and spontaneous sweating due to yin deficiency.

4. Allantoin contained in Dioscorea opposita Thunb. can cure dermatoses. It has the functions of anesthesia and analgesia, and can promote epithelial growth, diminish inflammation and inhibit bacteria. It is often used to treat chapped hands and feet, ichthyosis and various keratinized dermatoses. ?