Why can't leftovers stay overnight?

"waste" always happens when people think they are still well off, so is the waste of food. At the end of the supply chain, human beings have a large number of rich, perfect and glamorous ingredients to choose from, so they don't know the invisible consumption in the whole industrial chain and the ecological limit that they will face because of these large wastes. Those foods that do not meet the supermarket purchasing standards, but are completely edible: radishes that are too small, tomatoes that look irregular, and crooked oranges, have all been discarded. If you pay a little attention in your life, you will find that the waste of food is everywhere. For example, the most common sliced bread in supermarkets or bakeries, the crust at both ends of which has been discarded before it is put on the shelves. In some revolving sushi restaurants that emphasize the original flavor and absolute freshness of ingredients, slogans will tell you that the life of each prepared sushi here will not exceed 3 meters on the turntable, and waiting for them at the end of the turntable is a trash can that swallows sushi. Those foods that are completely edible, but only because they are picky about the shape or size of bananas, may be thrown away. These abandoned foods in the supply chain are called "leftover foods". They are not those foods that are spoiled and difficult to swallow, but those that are intact and fresh. There are usually three sources of surplus food: farms, a large number of raw materials that have been eliminated in the procurement process, usually ingredients with insufficient size and shape, or fruits with less pleasant taste; Supermarket/vegetable market, those temporary foods that are left behind and are no longer full and shiny; Restaurants, because of the daily loss of ingredients caused by too many meals. The leafy vegetables served on the table are pinched off and only the middle part is left; The apples in the supermarket are all crystal clear, and the crooked melons and cracked dates have long been kicked out; Many people have only seen the peeled jackfruit, but they don't know that the silk and core in it can still be used to make soup. In fact, there are many ingredients in life that can be eaten, and the nutrition may be better than the main ingredient, and the taste is unique. As long as the pulp is not spoiled, bananas can grow spots and turn black. There are four main reasons: first, mechanical damage, such as bumping during transportation; Second, when it encounters mold, the banana that is "injured" will be mildewed and rot if it encounters mold; Third, it turns black after cold storage. As a tropical fruit, bananas can't stand the low temperature. If they are put into the refrigerator, they will be frostbitten. Fourth, I haven't eaten it for too long, and it's overcooked.