How Food Grows and Dies
All food is organic and contains cells that grow and die. We use food when it is ripe or mature. Anyone who's ever grown tomatoes or any other vegetable understands how quickly a ripe tomato can turn dark and mushy. Eventually, the fruit begins to break down into its molecular components, like water and sugar, making a puddle under the tomato. All of the material we use as food follows the same process. The speed of the process determines how "perishable" the food is.
How Food Spoils
At any point during its growth, organisms contain beneficial bacteria that eat dead cells and protect the organism from pests and parasites. Some types of bacteria, though, harm the organism and create dead spots that we call rot. Most bacteria live harmlessly on or in food until the organism stops regenerating cells. When that happens, bacteria begin to consume the food.
The Fungus Among Us
Another organism that can threaten food is fungus. Fungi grow from spores that travel on the wind and are more successful during wet, warm springs and early summers. Fungi like mushrooms are used as food but others pose a threat to foods. Blossom end rot is a fungus common to tomatoes due to over-damp conditions as the fruit emerges from the blossom in early spring.
How Refrigerators Work
The first refrigerators used huge blocks of ice to keep an insulated box cool. During the last half of the twentieth century, the ice box was replaced by an appliance that used coils filled with a frigid liquid, or refrigerant, that was compressed and pumped through metal coils to cool the box evenly. This system was more easily regulated than the old ice box and now refrigerators can be regulated to keep food at a constant temperature and freezers can keep food frozen without dehydrating it.
What Refrigeration Does to Food
When refrigerators cool food to a temperature just above freezing, it slows the death and regeneration of cells in the food, prolonging the ripening process. A green tomato will stay green almost indefinitely (or until it dehydrates completely) in a refrigerator vegetable bin. By slowing the growth of cells, a refrigerator also controls the amount of food available to bacteria and limits their ability to flourish. If food is cooled or frozen, most bacteria will die because of the hostile environment. Cold air also wrings out humidity, which kills many fungus spores. This means that refrigerated food lasts longer and stays fresher than food that is not refrigerated.
- Photo Credit Microsoft, DRW & Associates, Inc.
Why Does Food Spoil in the Refrigerator?
Food spoils in the refrigerator for any number of reasons. Food spoilage is indicated by mold growing on the surface, fresh foods...