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.
Pathogens: Harmful Bacteria
The 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 Escherichia 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.
2. Safety and Hygiene procedure used to prevent food spoilage and food poisoning.
So how do we control these nasties? One way would be to starve them out. 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: Temperature
pH Level (Acidity)
Keeping cold foods cold
Keeping cold foods cold means storing them at temperatures between 4°C , which is the normal temperature of a fridge, down to -18°C, which is where you want your freezer to be. At freezing temperatures, bacterial growth slows to nearly nil. Freezing doesn't kill them, though, all it does is make them cold. Once you thaw that food, any bacteria that were there before freezing will just warm up and start multiplying again.
Keeping hot foods hot
Keeping hot foods hot presents other challenges. Bacterial growth slows down once again at temperatures hotter than 60°C so hot foods that are being served on a buffet, for example, must be kept hotter than that at all times. Keep in mind that 60°C doesn't kill bacteria, it only stops them from multiplying. If you actually want to kill bacteria, you've got to heat them up to at least 75°C. The same rule applies to cooked food that should happen to drop below 60°, you get an hour, total. After that, you either need to heat it up to 75°C again or throw it away and it can only be reheat once. If it drops below 60°C a second time, you need to throw it out.
Like all living organisms, bacteria need water to survive. Foods high in moisture like meats, poultry, seafoods and dairy products, as well as fruits and vegetables, are prime breeding ground for harmful bacteria. Low-moisture foods, including dried grains and legumes such as rice or beans, will typically keep for a very long time without spoiling or grow bacteria.
Another aspect of the moisture factor is that through a process called osmosis, sugar and salt actually suck the moisture out of bacteria, effectively killing them by dehydration. As a result, a high salt and/or sugar content will tend to preserve foods, which is why salt and sugar are used in brining and curing of meats. pH level (acidity)
pH is a measure of how acidic something is, and it runs on a scale of 0 to 14. Anything lower than 7 is considered acid and anything higher than 7 is considered base or alkaline. A value of 7 would be considered neutral. Bacteria can't stand anything too acidic or too alkaline. For bacteria to thrive, the pH environment needs to be neutral.
Food Hygiene Procedures
All food handlers should:
(a) Thoroughly wash (using warm water and liquid soap) and dry (using disposable towels or air, not apron) their hands regularly when handling food, in particular: Before handling food
Immediately after handling raw food, especially raw meat or poultry After going to the toilet
After handling money
After blowing their nose, sneezing or coughing
(b) Wear clean...