Microorganisms in food

The destmction of microorganisms in foods follows the same kinetic relationship as for other materials. The process is strongly induenced by the nature of the food, size of the container, and temperature. Industry-wide standards have been estabUshed by the National Canners Association (24). 

Scheu, R M. Berghof, K. Stahl, U. Detection of pathogenic and spoilage microorganisms in food with the polymerase chain reaction. Food Microbiol. 1998,15, 13-31. 

ICMSF (2005), Fruits and fruits products , in Microorganisms in Foods 6 Microbial Ecology of Food Commodities, Kluwer Academic/Plenum Publishers, New York. 

Halasz, A., Barath, A., Simon-Sarkadi, L. and Holzapfel, W.H. (1994). Biogenic amines and their production by microorganisms in food. Trends Food Sci. TechnoL, 5, 42. 

Figure A2.2.1 Water activity stability map (adapted form Labuza, 1970). A representation of a typical sorption isotherm for food materials and of the effects of water activity on the relative reaction rates of several chemical processes, as well as the growth of microorganisms, in foods are shown.

C What are the environiuental factors that affect the growth rate of microorganisms in foods ... 

C What is the effect of cooking on the microorganisms in foods Why is it important that the internal temperature of a roast in an oven be raised above 70°C ... 

C How can the contamination of fotxls with micro-otgaiiisms be prevented or minimized How can the gtowth of microorganisms in foods be retarded How can the microorganisms in foods be destroyed ... 

Pure water has an a of 1.00 and a saturated NaCl solution an a, of 0.75. Evaluation of techniques and instrumentation has been investigated by Labuza et al [4]. Table 3.57 illustrates aw and the growth of microorganisms in foods and Table 3.58 the minimal a for some microorganisms of significance to public health [5],... 

Table 3.57 Water activity and growth of microorganisms in food...

The cause of food spoilage was affirmed in 1864 by Louis Pasteur who showed that microorganisms in foods were the cause of such contamination. He subsequently found that microbes were killed by heating and that sealed containers could be used to preserve food by preventing recontamination from atmospheric air. 

Caplice, E. and Fitzgerald, G.F. 1999. Food fermentations Role of microorganisms in food production and preservation. International Journal of Food Microbiology 50 131-149. 

Source International Commission of Microbiological Specifications for Foods (ICMSF) Microorganisms in Food, Vol. 5. New York Blackie Academic and Professional, 1996. 

McClure, P.J., Blackburn, C. de W., Cole, M.B., et al. 1994. Modeling the growth, survival and death of microorganisms in foods The UK Food Micromodel approach. International Journal of Food Microbiology 23 265-275. 

Busta, F.F. Practical implications of injured microorganisms in food, /. Milk Food TechnoL, 39, 138, 1976. 

A.A.V.V. (1996) ICMSF, Microorganisms in foods 5, Microbial specifications of food pathogens. 

Laroche, C., Eine, R, and Gervais, P. 2005. Water activity affects heat resistance of microorganisms in food powders. International Journal of Food Microbiology 97 307-315. 

Smiddy et al. (2005) confirmed higher baro-resistance of bacteria in oysters than in bnffer, which indicated that stndies of high-pressure-induced bacterial inactivation in bnffer systems may not predict inactivation of microorganisms in foods. Calci et al. (2005) indicated that 6-log redaction of Hepatitis A virus could be achieved via application of high pressure (350-400 MPa). Li et al. (2009) demonstrated that high-pressnre treatment (400 MPa, 5 min, 0°C) of oysters contaminated with murine norovirns-1 could reduce the levels of contaminant to undetectable levels. 

Troller, J. A. (1980). Influence of water activity on microorganisms in foods. Food Technol. 34(5), 76. 

However, much more attention is now devoted to pathogenic microorganisms in food, E. coli 0157 H7 Salmonella spp.. Listeria monocytogenes, Campylobacter spp. 

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