c. This fact is extremely important in preventing foodborne illness. It is the
principle behind dried foods, such as dried fruits, meats, and milk. However, once the
food becomes wet, the bacteria can begin to grow and will contaminate the food.
d. The sugar and salt content of a food can affect the water activity. Generally,
foods that have a salt content of 15% or more will have a water activity below 0.85;
likewise, foods that are 50% to 60% sugar will have a water activity below 0.85.
Therefore, very salty and sugary foods will also inhibit bacterial growth.
1-14. BACTERIAL GROWTH AT A FOOD SERVICE FACILITY
The requirements for the growth of bacteria have been discussed separately in
paragraphs 1-8 through 1-13. At a real food service facility, however, these conditions
often work together to cause dangerous bacterial growth in foods. For example, moist
food left out in a warm, damp room for several hours will almost certainly be
contaminated. The reverse also applies. Controls on temperature, moisture, time, etc.,
can greatly reduce the chances of rapid bacterial growth and food contamination. Your
duty as an inspector is to ensure that facilities are applying the necessary controls and
to be alert to situations favoring bacterial growth.
1-15. POTENTIALLY HAZARDOUS FOOD
a. Potentially hazardous food is food that can support the rapid growth of
harmful microorganisms, particularly bacteria. Strictly speaking, when microorganisms
occur naturally in or enter a food, the microorganisms have contaminated the food.
However, in this subcourse and in many other references, contamination means the
situation that occurs when microorganisms grow to dangerous levels in potentially
b. Not all foods offer the conditions necessary for bacterial growth. Coffee, tea,
and dried fruit, with water activities below 0.85, are not hazardous because they do not
provide enough moisture for the growth of disease-causing bacteria. Likewise, pastries
and candies with a high sugar content (water activity below 0.85) will not support the
growth of harmful bacteria.
c. Other foods, termed potentially hazardous foods, support rapid bacterial
growth. The growth rate may vary depending upon how ideal the environment is.
Hamburger, for example, is a potentially hazardous food. Hamburger that has been left
out in a warm room for several hours will become contaminated quickly. Refrigerated
hamburger will also become contaminated, but much more slowly since cold
temperatures decrease bacterial growth.
d. Obviously, food service facilities must take extreme care with potentially
hazardous foods as they are the source of most outbreaks of foodborne illness. Many
Army regulations for food sanitation are designed to control the conditions under which
potentially hazardous foods are stored, prepared, and served.