cell can produce a thousand new cells and in several hours, billions of new cells. Due
to this rapid growth bacteria can contaminate food very quickly.
b. In order for bacteria to reproduce and grow, certain requirements must be
met. These requirements involve food, pH, temperature, time, oxygen, and moisture.
As a preventive medicine specialist, you will be inspecting food service facilities to
determine that they are following Army regulations. Most of these regulations involve
controlling conditions so that bacteria are not encouraged to grow. Paragraphs 1-8
through 1-13 will discuss each of the requirements for bacterial growth.
1-8.
FOOD REQUIREMENTS OF BACTERIA
Like all living organisms, bacteria must have food. Many bacteria consume the
same food as humans do and will grow freely in it. This makes a food service facility
1-9.
pH REQUIREMENTS OF BACTERIA
Most bacteria causing foodborne disease grow best in materials that are neither
strongly acid nor strongly alkaline.
a. The pH scale is a measurement of how acidic or alkaline a substance is.
Most bacteria grow in the middle of the pH scale between a value of pH 6 and pH 8. In
fact, most of the bacteria causing foodborne disease will not grow in foods with a pH
below 4.5.
Microorganisms
causing food-
borne diseases
will not grow
below this point
NEUTRAL POINT
1
2
3
4
4.5
5
6
7
8
9
10
11
12
13
14
ACID
ALKALINE
Figure 1-1. The pH scale.
MD0181
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