Why does the chicken in the supermarket have no head? Chicken head may be made into a popular beauty needle

When you buy chicken in the supermarket, have you ever considered a question: where are the chicken heads and feet? After chicken feet are cut, they can be made into other food. Few people eat chicken heads. So what’s the use of chicken heads? < / P > < p > hyaluronic acid, or hyaluronic acid, you should have heard that hyaluronic acid is the main material for filling lips and chin. This glycosaminoglycan is a key moisturizing and filling material used in many cosmetics and plastic surgery. < / P > < p > hyaluronic acid also has high medical value, such as protecting eyeball during operation, reducing inflammation of rheumatoid joint, preventing scar tissue after operation, etc. < / P > < p > hyaluronic acid was first discovered by French chemist Portes in 1880. It was rediscovered and studied by Karl Meyer of Columbia University in 1934. < / P > < p > Meyer found that the vitreous body of bovine eyeballs is filled with this substance, and hyaluronic acid is used to maintain the shape of bovine eyes. In fact, all vertebrates have hyaluronic acid, because it is the main component of extracellular matrix, synthesized by cell membrane, plays a protective and buffering role between cells, and is also related to inflammatory response and cell signal transmission. < / P > < p > a body weight of 70 kg contains about 15 g of hyaluronic acid. The highest content of hyaluronic acid was found in connective tissue, eyeball, umbilical cord and synovial fluid. < / P > < p > Meyer has a unique vision. Now hyaluronic acid injection has become a common treatment for rheumatoid arthritis. This treatment is called viscous supply, or cockscomb injection. According to the American Academy of Orthopaedics, hyaluronic acid makes joint movement easier and pain less. Not to mention the application of hyaluronic acid in the beauty industry. Due to its wide commercial value, the price of hyaluronic acid is as high as US $100000 per kilogram. < / P > < p > Meyer himself also tried to extract hyaluronic acid from bovine eyeballs. However, the extraction of hyaluronic acid from bovine eyeballs is not commercially feasible, because the process is cumbersome, and hyaluronic acid will be contaminated by other mucopolysaccharides. Later, on the basis of Meyer, endre Balazs, another scholar at Columbia University, discovered the method of extracting hyaluronic acid from Cock crowns in the 1940s. < / P > < p > originally, the content of hyaluronic acid in chicken crowns was the highest in known animal tissues, reaching 7.5 mg / g. Among all crowns, the crowns of roosters are larger than those of hens and castrates, so they are more favored by manufacturers. < / P > < p > hyaluronic acid was first used in animals. Since the 1970s, doctors have given horse racing with rheumatoid arthritis hyaluronic acid in their knees to reduce inflammation. Hyaluronic acid is also used in eye surgery in animals. It was not until the 1980s that hyaluronic acid was used in humans. Pharmacia, a Swedish pharmaceutical company with the patent for hyaluronic acid from Balazs, has launched a product Healon, which is used to protect the cornea during cataract surgery. Later, Healon became the synonym of hyaluronic acid. < / P > < p > until now, Sweden is still using Balazs’s original method to extract hyaluronic acid from Rooster crowns, but Healon’s patent was sold to Pfizer, another big pharmaceutical company. Another big producer of hyaluronic acid, jianzan, also uses the same method for extracting chicken crowns. < / P > < p > in order to produce a large amount of hyaluronic acid, Pfizer has bred cocks with super large crowns. Rolf Bergman, a professor of chemistry at Uppsala University in Sweden, who is involved in extracting hyaluronic acid from Rooster crowns, said the crowns of Pfizer’s White Leghorn roosters used to be so big that their heads couldn’t stand it. < / P > < p > in fact, chubby company of Japan, a salad dressing manufacturer with childhood memories, has an unknown industry, that is, extracting hyaluronic acid from chicken offal, which has become one of the world’s important suppliers of hyaluronic acid. < / P > < p > chicken crowns were sliced and cleaned in a large vat. Then acetone and other solvents were added to dissolve fat to obtain fat free chicken crowns. After the chicken comb without fat is continuously purified with sodium acetate and ethanol, the last thing left is hyaluronic acid. After step-by-step separation and disinfection, hyaluronic acid was made into dry powder. < / P > < p > making hyaluronic acid with bacteria can make people feel sick. Why not use good bacteria to make hyaluronic acid with bacteria? In fact, this is closely related to the survival strategy of Streptococcus. As early as 1937, Forrest E. Kendall, a biochemist at Columbia University, discovered that Streptococcus can produce natural hyaluronic acid without genetic modification. So the question is, why does Streptococcus need hyaluronic acid? < / P > < p > because the hyaluronic acid produced by Streptococcus is the same as the hyaluronic acid in the host, that is, the human body, it will not cause the alert of the host’s immune system, so these bacteria use hyaluronic acid to make a vest to wrap themselves and drill into the epithelial cells to avoid the attack of the immune system. < / P > < p > nowadays, Streptococcus zooepidemicus is the most commonly used Streptococcus species to produce hyaluronic acid. Streptococcus zooepidemicus can infect animals and humans. Horses are common victims of Streptococcus zooepidemicus. < / P > < p > it turns out that the human body contains enzymes that break down hyaluronic acid. These enzymes decompose the large molecule of hyaluronic acid into small molecule of hyaluronic acid, and finally the small molecule of hyaluronic acid is decomposed and absorbed. And too much small molecule hyaluronic acid can lead to inflammatory reaction, making the wound unable to heal continuously. < / P > < p > therefore, the larger the molecular weight of hyaluronic acid, the longer the time needed to be decomposed, and the better the duration and safety of the effect. In addition, the viscosity of hyaluronic acid is higher, so big companies like Pfizer have been making hyaluronic acid from chicken crowns. HEALTHY LIFE