You can tell if food has gone bad by looking or smelling it. Depending on the dish, the degree of food deformation will be different. For example, meat dishes or soups, if you see bubbles, white scum, or color changes, you should throw it away because bacteria have invaded.
Spoiled food often has a changed texture, such as being slimy, sticky or unusually dry. If they don’t feel the same to the touch as when they were first cooked, they may be spoiled.
Or if you see any signs of mold, throw away the entire food. Mold can spread and produce dangerous toxins.
However, with foods containing preservatives, the color may not change, making it easy for you to mistakenly think it is still fresh. In this case, the smell method can be applied. When food has unpleasant odors such as sour, foul, or bitter, it means the food has gone rancid or degenerated, and re-using it will pose a risk of poisoning.
To avoid wasting food, it’s best to cook enough to use, or mark the expiration date on leftovers before storing in the refrigerator. For example, the oldest food is always used first to ensure food quality. Before use, reheat properly.
Cooked food is only safe at room temperature for 2-4 hours, in the refrigerator for 2-3 days, and in the freezer (-18 degrees) for 1-2 months depending on the type of food. If left beyond this time, the risk of damage is very high.
Leftover food that changes color or has a strange odor should be thrown away. Illustration photo: Phuong Thao