"I study food science, so people often ask me how to eat and what to eat. When the price of fish drops, they worry, why the price drop? When dining out, they want to know if they might be eating rat meat. Of course, there are also questions like: should you wash meat after buying it?"
Ruan Guangfeng, director of the Communication Department for Food and Nutrition Information at Kexin, stated that generally, meat purchased may contain some pathogenic bacteria like Salmonella, as well as parasites. But despite that, some people advocate not washing it. In a 2014 science communication poster by the US Food Safety Inspection Service, it clearly told people not to rinse raw meat with water.
Why shouldn't you wash meat? First, during the rinsing process, pathogenic bacteria on the meat can contaminate other foods. Second, meat products are now uniformly slaughtered and processed, so they are not dirty. Third, only heating can effectively kill bacteria; washing doesn't eliminate them, it just moves them elsewhere.
For many people, it's hard not to wash meat after buying it. Since you must wash it, you should pay attention to a few techniques to prevent cross-contamination:
First, try to use a dedicated container, basin, or bucket for soaking and washing. Second, try not to rinse with running water. Third, try to place it at the bottom of the sink, with a slower and gentler water flow.
Of course, you should also have two cutting boards at home. One is for cutting raw meat, and the other is for cutting vegetables, fruits, and ready-to-eat foods to avoid cross-contamination.
If the meat is not used up, it involves refrigerator storage. It's important to remind everyone that a refrigerator is not a safe deposit box.
A refrigerator generally has two compartments: a refrigerated compartment and a frozen compartment. The freezer is at -18°C, where bacteria and microorganisms generally cannot survive. However, the refrigerated compartment is at 0-4°C, and some bacteria cannot be killed.
Among the bacteria present in the refrigerated compartment, Listeria is an extremely dangerous and active one. It can still grow slowly in the refrigerator, so Listeria is present in about two-thirds of refrigerators.
A US interagency food safety analysis report points out that among the four most common pathogenic bacteria causing foodborne diseases in the United States, Listeria is included, causing about 2,500 illnesses and 500 deaths annually in the US. In 2011, the EU reported 1,470 cases of Listeria infection, with a mortality rate of about 13%.
Listeria poses the greatest threat to pregnant women and children. The infection rate for pregnant women is 25 times higher than for the general population. After infection with Listeria, the miscarriage rate is about 30%, and it can also be transmitted to the fetus through the placenta. Newborns, after infection, can develop sepsis, meningitis, etc., with a mortality rate as high as 30%-70%.
From 2000 to 2009, there were 25 recorded cases of neonatal Listeria infection in mainland China, with a 56% mortality rate. From 1990 to 2007, Taiwan recorded 17 neonatal infections, of which 50% involved central nervous system infections and 29% were fatal. The Hong Kong Centre for Health Protection recorded 13 cases of pregnant women infected over five years, with nearly half (46%) losing their fetuses, including 3 miscarriages, 2 stillbirths, and 1 premature death.
The data from China is lower than that of the US and the EU, but the reason is not that our incidence rate is low, but that many such cases are not reported. Therefore, Chinese families must pay sufficient attention to the hygiene of their refrigerators.
How to avoid Listeria infection? Listeria is sensitive to heat. Generally, if the center temperature of food reaches 70°C and is maintained for more than 2 minutes, it can be killed.
Therefore, do not drink raw milk, cheese, and other dairy products that have not been pasteurized or thoroughly boiled; do not eat cold cuts, ham, venison, and other meats that have not been thoroughly heated; leftovers from the refrigerator cannot be eaten directly and must be reheated until thoroughly cooked.
In terms of personal hygiene, you should wash your hands before and after handling food, before eating, after using the toilet, or after changing diapers.
In summary, food safety must start in the kitchen. It cannot rely solely on "open kitchens and bright stoves"; it requires the armor of food safety knowledge.