Repeated freezing and thawing of fresh meat can produce a carcinogen that is harmful to human health.
Temperatures below the freezing point can quickly freeze the water in the cell membranes and protoplasm of fresh meat into solid ice crystals, which preserves the meat's texture and prevents the loss of nutrients, acting as a preservative. However, once it is thawed, the fresh meat loses a large amount of moisture. If it is frozen again, very little water is involved, and only the protoplasm in the cells provides support. If it is thawed and frozen again, only the fibrous tissue and fat in the meat play a role in freezing. Many nutrients in the meat are lost, the texture is reduced, and carcinogenic substances may even be produced. Therefore, do not repeatedly thaw and freeze fresh chicken, duck, and fish to avoid spoilage that is harmful to human health. We eat fresh fruits and vegetables, but is it the same for meat?
Some people prefer to eat fresh pork, thinking that newly killed pork is fresher than frozen meat. However, from a hygiene perspective, newly killed pork contains various bacteria, such as jaundice. In frozen pork, most of the bacteria in the meat are eliminated or die. In terms of meat quality, fresh meat often has excess juice and a stronger gamy and sour taste. Currently, both domestically and internationally, fresh meat is typically subjected to "aging treatment." This involves hanging the slaughtered livestock to drain excess water and blood before placing it in cold storage for preservation.
Furthermore, when thawing frozen meat, never use hot water, as it will cause the loss of fat and vitamins in the meat and also make it lose its fresh flavor.