What is Food Spoilage?Food spoilage is caused by tiny invisible organisms called bacteria. Bacteria live everywhere we live, and most of them don't do us any harm.
What Do Bacteria Like?As living organisms go, bacteria lead fairly simple lives. They don't walk or crawl, so the only time they go anywhere is when someone moves them. (See: What is Cross-Contamination?) Otherwise, they pretty much stay put, content to spend their time eating and making more of themselves.
Unfortunately, what they're eating is our food — especially foods that are high in protein, like meats, poultry, fish, eggs and dairy products.
To be sure, some of them will go for low-protein foods like fruits and vegetables, but those ones are a lot slower. Which is why an apple left on your kitchen counter for a couple of days would still be safe to eat, while a steak clearly would not.
Spoiled Food Vs. Hazardous FoodIt's important to note that spoiled food isn't necessarily dangerous food. For one thing, most people won't eat food that smells bad, looks slimy or whatever. And you can't get food poisoning from something you didn't eat.
Moreover, the microorganisms that cause ordinary food spoilage aren't necessarily harmful to us. In fact, centuries before refrigerators, the earliest sauces and seasonings were used to mask the "off" tastes and smells of food that had begun to spoil. This continues to be true in parts of the world where people don't have home refrigeration units (which, interestingly enough, includes most people alive on the planet today).
Pathogens: Harmful BacteriaThe bacteria we're concerned with from a food safety standpoint are the so-called "pathogens" that cause food poisoning. And these pathogens, like salmonella or E. coli, don't produce any smells, off-tastes or changes in the food's appearance — a slimy surface, for instance, or some sort of discoloration.
Microbe ManagementSo how do we control these nasties? One way would be to starve them out. As noted above, bacteria need food to survive. Get rid of the food, and your bacteria problem disappears. Unfortunately, though, without food, the field of culinary arts has very little to offer.
So we'll assume that food is part of the equation. Bacteria still have several other, quite specific, requirements, each of which can be controlled to some extent. Armed with this knowledge, we can effectively minimize the chances of food-borne illness. The factors we need to keep in mind include:
- pH Level (Acidity)