When it comes to leftovers, what people are most worried about is often nitrite.Nitrite itself does not cause cancer but it can be converted into nitrosamine in the human body and nitrosamine is carcinogen.Studies have found that the consumption of many nitrosamine for a long time has been related to esophageal cancer., stomach cancer, liver cancer, colorectal cancer and other cancers.
Where does nitrite in leftovers come from?
Plant foods that contain nitrate and nitrite, especially green leafy vegetables contain higher nitrate content.
If vegetables are stored for too long or not properly after cooking, the content of nitrite will increase.In general, the nitrite content will reach the highest level after the vegetable is stored in the refrigerator for 3-5 days.
In addition, although the nitrate reductase activity of food has been lost when cooked at high temperatures, the food is warmed more suitable for bacteria to grow.If leftovers for room temperature for long periods of time, the bacterial deodorant enzyme in bacteria can increase the concentration of nitrite, causing health danger.
Health risks of various leftovers:
- Leaf vegetables: After leaving at room temperature for 12 hours, the content of nitrite increases significantly, even some types exceed the nitrite safety limit in vegetables.After 24 hours of storage in the refrigerator, although the nitrite content is still in a safe value, the nutritional value has been greatly reduced.
- Fish, meat and soy products: These foods are low in nitrite but rich in protein, they can easily become a bacterial culture environment at room temperature.If you eat improperly, it is easy to cause gastritis and food poisoning.
- Rice and noodles: Rice left in the refrigerator for too long will be moldy.Do not eat leftover for more than two days.At the same time, the starch in cold rice will be "older", indigestion, especially detrimental to people with weak digestive systems.
Scientific food treatment method:
- Timely cooling: Cooked food should not be stored at room temperature for more than 2 hours and should be put in the refrigerator in time (preferably below 5 degrees C).
- Storage classification: Different leftovers should be preserved separately to avoid cross -contamination of bacteria.Sealed up with a plastic wrap or a lid container.
- Do not store leftovers for too long: Do not store leftovers for too long, it is best to eat all the next day.The longer the storage time, the more toxic substances are created.
- Heat thoroughly: leftovers must be heated up to 100 degrees Celsius before eating and boiling for more than 3 minutes.For larger meat dishes, make sure they are even hot.
Source and photo: QQ, Healthline