What is the easiest way to recognize foods contaminated with spoilage bacteria

In this item, we are ask to give certain identification that the food is already contaminated with spoilage bacteria. One of the indication is the difference is smell. When the odor is already too pungent, one might also observe the appearance of spots and totally change in color to unusual combinations

Food contaminated with spoilage bacteria can be recognized by the smell and color of the food.

 Food Bacteria change the smell of food and are easily detectable. Aside from that, food bacteria present causes the food to change in color. Other indicators would be the taste and texture of the food. Some come out smily or they taste bad.

Ithink the answer is 1. warmth