Generally overnight vegetables are kept in the refrigerator at low temperature and can be eaten the next day, but before consumption, you should judge whether the smell, color and texture of overnight vegetables have changed abnormally, and if no change occurs, they can be fully heated and eaten. If there is an obvious sour taste, softened texture and rotten overnight vegetables, they may have deteriorated and it is recommended to avoid further consumption. Dishes after cooking will make changes in the composition of food ingredients, which is conducive to digestion and absorption, while playing a sterilizing role, but leftover dishes placed for a long time will not only increase the rate of bacterial reproduction, but also produce nitrite and other substances harmful to the body, increasing the risk of poisoning. The low temperature environment in the refrigerator, although it can inhibit the reproduction of bacteria to a certain extent, slowing the rate of nitrite production, but does not guarantee that the dishes will not deteriorate, so although you can eat overnight dishes that have not deteriorated, but not recommended for long-term consumption, for not after a night time, but a long interval of dishes, but also need to minimize consumption. In addition to dishes that have been cooked, raw vegetables may also produce nitrites after a long period of time. When conditions allow, it is recommended to consume fresh vegetables as much as possible, and uneaten vegetables can be sealed with plastic wrap and stored temporarily in the refrigerator, but consumed as early as possible.