Microbiology of refrigerated meat There are many pertinent texts on the microbiology of meats. The purpose of this chapter is to examine briefly the types of micro-organisms and con- ditions that are of interest in relation to the refrigeration of meat and meat products. In a perfect world, meat would be completely free of pathogenic(food poisoning micro-organisms when produced. However, under normal methods the production of pathogen-free meat cannot be guaranteed. The internal musculature of a healthy animal is essentially sterile after slaughter (Gill, 1979, 1980). However, all meat animals carry large numbers of differ ent micro-organisms on the outer surfaces of the body and in the alimentary tract. Only a few types of bacteria directly affect the safety and quality of the finished carcass. Of particular concern are foodborne pathogens such Campylobacter spp, Clostridium perfringens, pathoge Escherichia coli, Salmonella spp, and Yersinia enterocolitica In general, the presence of small numbers of pathogens is not a problem because meat is normally cooked before consumption. Adequate cooking will substantially reduce the numbers, if not completely eliminate all of the pathogenic organisms present on the meat. Most meat-based food poison- ing is associated with inadequate cooking or subsequent contamination after cooking. The purpose of refrigeration is to reduce or eliminate the growth of pathogens so that they do not reach levels that could cause problems Normally the growths of spoilage organisms limit the shelf-life of meat The spoilage bacteria of meats stored in air under chill conditions include species of Pseudomonas, Brochothrix and Acinetobacter/Moraxella. In general, there is little difference in the microbial spoilage of beef, lamb, pork nd other meat derived from mammals(Varnam and Sutherland, 1995)1 Microbiology of refrigerated meat There are many pertinent texts on the microbiology of meats. The purpose of this chapter is to examine briefly the types of micro-organisms and con￾ditions that are of interest in relation to the refrigeration of meat and meat products. In a perfect world, meat would be completely free of pathogenic (food poisoning) micro-organisms when produced. However, under normal methods the production of pathogen-free meat cannot be guaranteed. The internal musculature of a healthy animal is essentially sterile after slaughter (Gill, 1979, 1980). However, all meat animals carry large numbers of differ￾ent micro-organisms on the outer surfaces of the body and in the alimentary tract. Only a few types of bacteria directly affect the safety and quality of the finished carcass. Of particular concern are foodborne pathogens such as Campylobacter spp., Clostridium perfringens, pathogenic serotypes of Escherichia coli, Salmonella spp., and Yersinia enterocolitica. In general, the presence of small numbers of pathogens is not a problem because meat is normally cooked before consumption. Adequate cooking will substantially reduce the numbers, if not completely eliminate all of the pathogenic organisms present on the meat. Most meat-based food poison￾ing is associated with inadequate cooking or subsequent contamination after cooking.The purpose of refrigeration is to reduce or eliminate the growth of pathogens so that they do not reach levels that could cause problems. Normally the growths of spoilage organisms limit the shelf-life of meat. The spoilage bacteria of meats stored in air under chill conditions include species of Pseudomonas, Brochothrix and Acinetobacter/Moraxella. In general, there is little difference in the microbial spoilage of beef, lamb, pork and other meat derived from mammals (Varnam and Sutherland, 1995)