Handbook of Meat Processing

482 Chapter 28

are too small to be seen without a micro-

scope. On the one hand, microorganisms

can be benefi cial to humans because of their

role in various geochemical cycles, such

as the phosphorous cycle, carbon and oxygen

cycles, nitrogen cycle, and sulfur cycle;

without them, the earth would not be

livable for humans. They are also important

in various fermented foods, such as wine,

cheese, beer, vinegar, bread, and soybean

products, and in the production of industri-

ally important acids, solvents, antibiotics,

steroids, enzymes, etc. They can even be

eaten as foods such as yeasts and single - cell

proteins. On the other hand, microorganisms

can spoil our food supplies and cause devas-

tating disease in animals and humans; if

unchecked, they could even destroy the

human race.

From the standpoint of the microorgan-

isms, however, they are simply trying to

fulfi ll their biological need to grow and per-

petuate themselves via sexual and asexual

reproduction. Like humans, they need water,

carbohydrates, protein, fat, mineral, vita-

mins, and the right combinations of gases,

temperature, pH, and other conditions in

order to grow and multiply and survive.

Therefore, there are no “ good ” microorgan-

isms or “ bad ” microorganisms in nature; we

can consider them harmful or benefi cial

according to how they affect us.

Defi nitions

There are three major microbial hazards in

food: spoilage microorganisms, food - borne

intoxications, and food - borne infections.

Spoilage Microorganisms

When large numbers of undesirable microor-

ganisms are present in raw, contaminated

cooked, or fermented food supplies, they

compete with the space and utilization of the

food ’ s nutrients; these are considered to be

spoilage microorganisms. Occasionally, the

emerging or reemerging in the food supply,
which makes tracking and controlling these
organisms more diffi cult. In addition, the out-
breaks can transcend national boundaries. In
2008 in the United States, an outbreak of
food - borne illness involving spinach con-
sumption resulted in an international effort to
trace the origin of the disease, which was
eventually tracked back to Mexico. Peanut
products also became a national sensational
case and many products were recalled in the
United States in 2008. Salmonella was the
culprit in that particular case. The list is long;
suffi ce it to say that outbreaks are constantly
evolving, while microbiologists are kept
busy tracking down these food - borne
diseases.
Fortunately, new developments in micro-
bial detection offer new methods and systems
to detect these organisms. Also, there are
better and more effi cient intervention strate-
gies and food - processing methods to con -
trol unwanted microorganisms. Thus, food
microbiologists, food scientists, epidemiolo-
gists, medical personnel, public health
workers, and consumer educators are charged
with the responsibility of studying the occur-
rence, enumeration, isolation, detection,
characterization, prevention, reporting, and
control of food - borne microorganisms in
food, water, and the environment — and then
educating the public in order to reduce
microbial hazards in food nationally and
internationally.

Synopsis of Introduction to Food

Microbiology by Fung (2009b)

Microorganisms are ubiquitous in our envi-
ronment, and they affect our daily lives
through their prolifi c biochemical activities
under ideal growth conditions. All living
things less than 0.1 mm in diameter fall into
the microscopic world of microbes. The
microbial world includes viruses, bacteria,
yeasts, molds, protozoa, algae, and other
organisms that at different growth stages