Fundamental Food Microbiology, Third Edition - Fuad Fathir

CONTENTS
467
CHAPTER 33
Control by Low Temperature
I. Inroduction ................................................................................................467
II. Objectives .................................................................................................468
III. Mechanisms of Antimicrobial Action ......................................................469
IV. Influencing Factors ...................................................................................470
A. Nature of Process ............................................................................. 470
B. Nature of Food .................................................................................471
C. Nature of Microorganisms ................................................................471
V. Methods ....................................................................................................472
A. Ice Chilling .......................................................................................472
B. Refrigeration .....................................................................................472
C. Freezing ............................................................................................473
VI. Conclusion ................................................................................................473
References............................................................................................................. 474
Questions ..............................................................................................................474
I. INTRODUCTION
The effectiveness of low temperature, especially freezing, in food preservation was
probably recognized by our ancestors at least in the last Ice Age, before 40,000 B.C.
Natural freezing and thawing could also have been used to preserve food during the
very early stages of civilization, ca. 10,000 to 12,000 B.C. In the colder regions of
the world, foods (e.g., meat, and fish) are still preserved in natural ice. Ice was used
by the wealthy Romans to reduce the temperature of foods. Until ca. 1800 A.D., ice
blocks from frozen lakes were cut, stored, and used to preserve raw foods (e.g.,
meats, milk, fish, and produce) by lowering the temperature. By 1840, with the help
of ammonia-compressed refrigerator units, ice blocks were produced commercially
and used to reduce the temperature of food for preservation. In 1880, refrigeration