255
Chapter 20
Spoilage of Specific
Food Groups
introduction
The predominant microbial types normally expected to be present in different food groups have
been listed in Chapters 2 and 4. Initially, a food produced under proper sanitary conditions generally contains microorganisms at a level (per g, mL, or cm 2 ) much lower than that at which spoilage
is detected. Subsequently, growth of some of the microbial species among those initially present
enables the microorganisms to reach the spoilage detection level. Many factors dictate which species will multiply relatively rapidly to become the predominant spoilage microorganisms. Along
with microbial types, food types, and food environments (both intrinsic and extrinsic factors)
have important roles in determining the predominant spoilage microflora in a food. These aspects
have been discussed in Chapters 4 and 6. In this chapter, predominant microorganisms associated
with the spoilage of different food groups are described. As the foods in each group have similarities in nutrient content and the environment, similar microbial types are generally associated with
spoilage. Pathogens are not included.
Fresh and Ready-to-eat Meat Products
Raw Meat
Fresh meats from food animals and birds contain a large group of potential spoilage bacteria
that include species of Pseudomonas, Acinetobacter, Moraxella, Shewanella, Alcaligenes, Aeromonas,
Escherichia, Enterobacter, Serratia, Hafnia, Proteus, Brochothrix, Micrococcus, Enterococcus,
Lactobacillus, Leuconostoc, Carnobacterium, and Clostridium, as well as yeasts and molds. 1–3 The
predominant spoilage flora in a meat is determined by nutrient availability, oxygen availability,
storage temperature, pH, storage time of the product, and generation time of the microorganisms present in a given environment. Post-rigor meats are rich in nonprotein nitrogenous (NPN)
compounds (ca. 13 mg/g amino acids and creatine), peptides, and proteins, but contain low
Chapter 20
Spoilage of Specific
Food Groups
introduction
The predominant microbial types normally expected to be present in different food groups have
been listed in Chapters 2 and 4. Initially, a food produced under proper sanitary conditions generally contains microorganisms at a level (per g, mL, or cm 2 ) much lower than that at which spoilage
is detected. Subsequently, growth of some of the microbial species among those initially present
enables the microorganisms to reach the spoilage detection level. Many factors dictate which species will multiply relatively rapidly to become the predominant spoilage microorganisms. Along
with microbial types, food types, and food environments (both intrinsic and extrinsic factors)
have important roles in determining the predominant spoilage microflora in a food. These aspects
have been discussed in Chapters 4 and 6. In this chapter, predominant microorganisms associated
with the spoilage of different food groups are described. As the foods in each group have similarities in nutrient content and the environment, similar microbial types are generally associated with
spoilage. Pathogens are not included.
Fresh and Ready-to-eat Meat Products
Raw Meat
Fresh meats from food animals and birds contain a large group of potential spoilage bacteria
that include species of Pseudomonas, Acinetobacter, Moraxella, Shewanella, Alcaligenes, Aeromonas,
Escherichia, Enterobacter, Serratia, Hafnia, Proteus, Brochothrix, Micrococcus, Enterococcus,
Lactobacillus, Leuconostoc, Carnobacterium, and Clostridium, as well as yeasts and molds. 1–3 The
predominant spoilage flora in a meat is determined by nutrient availability, oxygen availability,
storage temperature, pH, storage time of the product, and generation time of the microorganisms present in a given environment. Post-rigor meats are rich in nonprotein nitrogenous (NPN)
compounds (ca. 13 mg/g amino acids and creatine), peptides, and proteins, but contain low