Most Chinese people are frugal and like to save leftover food for the next day, but some leftovers should not be eaten.
I. Soup
The best way to store soup is not to add seasonings like salt. After cooking, ladle out the portion for the day with a clean spoon. For any leftover soup, it's best to store it in a clay pot in the refrigerator. This is because leaving soup in aluminum or stainless steel pots for a long time can cause chemical reactions. It should be stored in glass or ceramic containers.
II. Fish and Seafood
Fish and seafood can easily produce protein degradation products overnight, which can damage liver and kidney function.
III. Bulk Braised Foods
Bulk braised foods should be eaten on the same day and not left overnight. From a food safety perspective, this is unhygienic. If possible, it's best not to eat leftover braised foods. Food experts remind us that even food stored in the refrigerator is not absolutely "safe." Refrigerators can easily grow mold and harbor psychrophilic bacteria.
IV. Tea
Overnight tea has most of its vitamins lost after a long time. The proteins and sugars in the tea become nutrients for bacteria and mold to grow on.
V. Leafy Green Vegetables
Some leafy green vegetables contain a high amount of nitrates. If cooked and left for too long, bacteria can break down the nitrates into nitrites, which are carcinogenic and cannot be removed by reheating.
VI. Tremella (Silver Ear Mushroom)
Both indoor-cultivated and wild-harvested tremella contain a high amount of nitrates. If cooked and left for a long time, bacteria can break down the nitrates into nitrites.
VII. Eggs
If eggs are not fully cooked, consuming the undercooked yolk overnight, especially if stored improperly, can easily lead to bacterial growth, causing issues like indigestion and gas. However, if the eggs are fully cooked and stored properly at a low temperature in a sealed container, they are generally safe to eat.