INTRODUCTION TO MICROBIOLOGY
Section I. AGENTS CAUSING FOOD SPOILAGE
a. Early Man and Food. The history of man's civilization can be directly
correlated with his knowledge of the science of the preservation and curing of foods.
Preserving and curing food is directly related to the microbiology of the particular food.
While Early Man had no conclusive evidence of the existence of microorganisms, he did
know that food would spoil under certain conditions, and he was able to take certain
corrective measures to prevent this spoilage. Man must have a constant source of food
in order for civilization to advance. The human race has lived under two different
nutritional systems. Under the first system, which terminated about 6000 B.C., man
was essentially a food gatherer. He was concerned only with obtaining food to continue
to exist and was not able to gather or produce food in sufficient quantities so that there
was leisure time for cultural pursuits. About 6000 B.C., man became a food producer.
Food then became available in sufficient quantities so that there was sufficient food for
periods of leisure and, in fact, certain groups were freed of the necessity of producing
food and were able to become scholars. Cereal and livestock farming are essential to
the founding of civilization. With the growing of cereals and domestication of livestock,
man finally achieved the status of a food producer.
b. The Necessity of Preserving Food. Man, as a food producer, was able to
settle in one locale and remain there on a permanent basis. The food he produced, of
course, was subject to spoilage and he had to become adept at preserving it. Cereals
were stored so as to alleviate the losses caused by insects. Gradually, the science of
preserving meat products evolved, so that it was possible to slaughter animals and not
be compelled to eat the meat within a twenty-four to forty-eight hour period.
c. Snow and Ice. Snow and ice have been used for many centuries to preserve
meat products. Alexander the Great used snow to preserve food, and also used it to
cool his wine. The Romans used snow to pack prawns (resembling shrimps) and other
perishable foods. Chaff was often mixed with the snow to slow down the rate of
melting. Such a mixture of snow and chaff was obviously unsanitary because
microorganisms are not destroyed in such a mixture.
d. Salt. Salt has been used as a preservative since the beginning of recorded
history. It was used in China as early as 1200 B.C. The Jews were early users of salt
to preserve meat products. This would seem natural because of their access to the
supply of salt from the Dead Sea. Salt-fish was a common commodity in Ancient
Greece. The Romans were schooled in the use of salt as a preservative by the Greeks.
The Romans used it in preserving fish and pork products.