Food poisoning is a common illness caused by consuming contaminated food or drink. The most common causes of food poisoning are bacteria, viruses, parasites, and toxins. Food poisoning symptoms include nausea, vomiting, abdominal cramps, and diarrhea. While most cases of food poisoning clear up on their own within a few days, some cases can be severe and require medical treatment.
A common question many people have is whether thoroughly cooking contaminated food can kill the pathogens that cause food poisoning and make the food safe to eat again. The answer depends on the specific pathogen causing the contamination.
Can bacteria that cause food poisoning be killed by cooking?
Many common causes of bacterial food poisoning, such as salmonella, E. coli, and campylobacter, can be killed by proper cooking. These bacteria are destroyed and made safe to eat when foods are cooked to the recommended internal temperatures:
| Food | Minimum Internal Temperature |
|---|---|
| Ground meats | 160°F (71°C) |
| Poultry | 165°F (74°C) |
| Fish/seafood | 145°F (63°C) |
| Eggs | 160°F (71°C) |
| Leftovers | 165°F (74°C) |
Reaching these high internal temperatures is sufficient to destroy salmonella, E. coli, campylobacter, and other foodborne pathogens. So thoroughly cooking contaminated foods to the proper temperature can kill bacteria and make the food safe to eat again.
It is critical to use a food thermometer to check that foods have reached the minimum safe internal temperatures. You cannot rely on simply looking at the color and texture of food to determine doneness, as some bacteria can survive in foods that look properly cooked.
Can viruses that cause food poisoning be killed by cooking?
Common viral causes of food poisoning include norovirus, hepatitis A virus, and rotavirus. Unlike bacteria, viruses cannot reproduce or grow in food. Cooking contaminated food does not destroy viruses that may be present, though it may inactivate some of them.
Viruses are generally more heat stable than bacteria. Research shows that norovirus can survive temperatures as high as 140°F (60°C). So cooking food thoroughly cannot be relied upon to kill norovirus or other foodborne viruses.
Proper handwashing is key to preventing viral food poisoning, as many viruses are transmitted by the fecal-oral route. Contaminated food handlers who do not wash hands adequately after using the restroom can transmit viruses to the food they touch.
Can parasites that cause food poisoning be killed by cooking?
Parasites such as Cryptosporidium, Giardia, cyclospora, and Toxoplasma gondii can contaminate food and water and cause foodborne illness. The main sources of parasitic food poisoning include undercooked meat, fruits and vegetables contaminated with feces, and contaminated drinking water.
Cooking food thoroughly can kill some parasites, while others have greater heat tolerance. For example:
| Parasite | Vulnerability to Heat |
|---|---|
| Toxoplasma gondii | Killed by freezing to -13°F (-25°C) or heating to 149°F (65°C) |
| Cryptosporidium | Highly heat resistant, can survive pasteurization |
| Giardia | Killed by heating to 131-140°F (55-60°C) |
Due to their high heat tolerance, parasitic causes of food poisoning are best prevented by:
– Thoroughly washing fruits and vegetables
– Cooking meat to safe internal temperatures
– Avoiding cross-contamination between cooked and raw foods
– Only drinking clean, treated water
Can toxins that cause food poisoning be destroyed by cooking?
Certain toxins and chemicals can contaminate food and cause food poisoning, including mycotoxins, heavy metals like lead, biogenic amines, and pesticide residues. These toxins are not alive like bacteria, viruses, and parasites – they are hazardous chemicals.
Simply cooking contaminated food cannot destroy or inactivate many of these toxins and chemicals. For example:
| Toxin/Chemical | Effect of Cooking |
|---|---|
| Mycotoxins | Heat stable, not deactivated by cooking |
| Heavy metals like lead | Cannot be destroyed by cooking |
| Biogenic amines | Heat stable compounds |
| Pesticide residues | Remain after cooking |
The only way to prevent food poisoning from toxins is to avoid consuming contaminated food and drinks in the first place. Practicing safe storage, preparation, and handling methods reduces the risk of chemical contamination.
Can reheating food prevent food poisoning?
Leftovers and prepared foods that have been cooled should always be reheated thoroughly to 165°F or until steaming hot before eating. This kills any bacteria like salmonella or E. coli that may have multiplied on the food during storage.
However, reheating does not make contaminated food safe if it has a virus, parasite, or toxin present. These cannot be killed through reheating alone.
What are other ways to prevent food poisoning?
While thorough cooking and reheating kills many pathogens, other food safety practices are needed to prevent food poisoning:
| Practice | Details |
|---|---|
| Proper hand hygiene | Wash hands with soap and water before, during, and after food preparation. |
| Avoid cross-contamination | Use separate cutting boards and utensils for raw and cooked foods. |
| Sanitize surfaces | Clean counters, cutting boards, and tools with hot soapy water. |
| Store food properly | Keep refrigerated foods below 40°F. Do not leave perishable foods sitting out for >2 hours. |
Following basic food safety guidelines is important, even when cooking foods thoroughly to kill pathogens. Preventing contamination in the first place is the best way to avoid food poisoning.
Conclusion
Thoroughly cooking foods can destroy many common food poisoning bacteria such as salmonella, E. coli, and campylobacter. However, viruses, parasites, and toxins that cause foodborne illness can be heat resistant and may survive cooking.
While cooking is one important step, overall food safety requires preventing contamination through proper handling, preparation, storage, and sanitization from farm to fork. Practicing good hygiene and following food safety guidelines reduces the risk of food poisoning, even when dangerous pathogens cannot be killed through cooking alone.