Fundamental Food Microbiology, Third Edition - Fuad Fathir

474 FUNDAMENTAL FOOD MICROBIOLOGY
REFERENCES
1. Kraft, A.A., Refrigeration and freezing, in Psychrotrophic Bacteria in Foods, CRC
Press, Boca Raton, FL, 1992, p. 241.
2. Ray, B., Kalchayanand, N., and Field, R.A., Meat spoilage bacteria: are we prepared
to control them?, Natl. Provision., 206(2), 22, 1992.
3. Ray, B., Kalchayanand, N., Means, W., and Field, R.A., The spoiler: Clostridium
laramie, Meat Poult., 41(7), 12, 1995.
4. Ray, B., Enumeration of injured indicator bacteria from foods, in Injured Index and
Pathogenic Bacteria, Ray, B.. Ed., CRC Press, Boca Raton, FL, 1989, p. 10.
5. Olson, J.C. and Nottingham, P.M., Temperature, in Microbial Ecology, Vol. 1, Silliker,
J.H., Ed., Academic Press, New York, 1980, p. 1.
6. Speck, M.L. and Ray, B., Effects of freezing and storage of microorganisms from
frozen foods: a review, J. Food Prot. 40, 333, 1977.
7. Kalchayanand, N., Ray, B., and Field, R.A., Characteristics of psychrotrophic
Clostridium laramie causing spoilage of vacuum-packaged refrigerated fresh and
roasted beef, J. Food Prot. 56, 13, 1993.
QUESTIONS
1. List the microbiological objectives of low-temperature preservation of food. How
do these objectives differ from those for food preserved by heat?
2. Briefly discuss the mechanisms of microbial control by reducing the temperature
of a food to 10ºC, to –1ºC, to –10ºC, and to –20ºC.
3. List the major factors that need to be considered for effective control of microorganisms
in a food at low temperature, and briefly discuss the importance of each.
4. Discuss the microbial implications of the following in low-temperature preservation
of foods: (a) fluctuation of storage (refrigerated and frozen) temperature, (b)
slow cooling of a warm food, and (c) slow thawing of a frozen food.
5. Briefly discuss the microbiological problems of foods stored by chilling, refrigeration,
and freezing.
6. List the psychrotrophic pathogens that can cause food hazard in refrigerated readyto-eat
foods and suggest a method that can be used to overcome the problem
(consult Chapter 40).