What method can NOT effectively prevent trichinosis?

The method that cannot effectively prevent trichinosis is refrigerating pork for 30 days. Trichinosis is caused by the consumption of undercooked meat from animals infected with Trichinella larvae, particularly found in pork.

Refrigeration does not kill these larvae effectively; while it can slow down the growth of bacteria, it does not eliminate parasites such as Trichinella. To ensure the safety of pork, it is critical to thoroughly cook it to the appropriate internal temperature, which is effective in killing the larvae. Freezing pork can also be effective, but it requires specific conditions such as extremely low temperatures maintained for a sufficient duration, generally at least three weeks. Purchasing pork from approved sources also helps, as it ensures that the meat has been inspected and deemed safe for consumption.