To test the food is still suitable for consumption or not, here are some foods that you can identify characteristics as will be damaged, as reported by eHow
The fish usually will begin to deteriorate if it is more than three days. When it starts to rot, the fish will generally remove the odour is very strong. See also the change in colour to a dull point. If the fish looks brown, yellow, or greyish, or even just look at the edges, remove the fish.
Eggs are difficult to analyze whether it was good or not. To test the quality, you can take a bowl that has been filled with water. Way, take the eggs and make the crack, put it into the water and observe, if the air out of the egg, it was a sign the egg is broken. Fresh eggs will float and no air comes out.
Steak has its own charm, especially when it is baked, but the fire burnt not the key to making a good steak. Meat that is not stored properly will be the growth of harmful microorganisms media such as E.coli and salmonella, which makes the steak smell is fragrant.
When the restaurant is able to store the meat until about two weeks, not so with the meat shop. Meat can only be stored for much shorter exposure to outside air. When the meat was slimy and unpleasant odour, you should discard. » Read more..