If the food has been prepared or cooked, it is now brought to its final edible state by quenching with water, special dressing, and brief gratinating or gratinating. However, the food should not be kept warm or left standing for a long time, because additional and prolonged exposure to heat after cooking leads to further losses of nutrients and vital substances (macro- and micronutrients) in the food. In addition, liquid and thus water-soluble vitamins are removed from the food. It increasingly leaches out, which means that increased losses of minerals and trace elements are to be expected. Fruit or vegetables that have already been prepared – cut or peeled – are particularly susceptible to oxygen and free radicals if they are left to stand for a long period. They are provided with a larger attack surface, which facilitates the attack. They break down essential vitamins in the food, such as vitamins A, C, B2 and B6, and due to increased enzyme activity and bacterial proliferation, it is more rapidly exposed to spoilage.
If food is not consumed after cooking, but is stored for several more days in the refrigerator or other cool room facilities, a health-promoting effect of the food can no longer be guaranteed. The external factors – light, oxygen, temperature, free radicals and pollutants – act together on the food, adversely affecting it and accelerating the destruction of vital substances (micronutrients), leaching and spoilage. The quality deteriorates tremendously, making the food more of a health risk to humans. The more time the food is stored, the more bacteria and other harmful substances spread in the food and the more serious the micronutrient losses are. If the food is spoiled, the vital substances (micronutrients) have also been completely destroyed and degraded. Spoiled food should be thrown away immediately. To avoid endangering health, cutting out spoiled areas is more likely to be avoided, as the bacteria have usually already spread to other areas of the food.
