Meat, poultry and seafood.

A muscle food, including meat, poultry, and seafood, is described as spoiled when it is considered unacceptable by consumers based on its sensory characteristics. Economic losses as well as the food wasted and loss of consumer confidence due to spoilage, however, are of major significance. Among bacteria, genera in the family Enterobacteriaceae, Photobacterium phosphoreum, Shewanella (Alteromonas) putrefaciens, Brochothrix thermosphacta, Pseudomonas spp., Aeromonas spp., and lactic acid bacteria have been found to be major contributors to muscle food spoilage, depending on the product type and the conditions surrounding the product. Chemical (chlorine, organic acids, inorganic phosphates, proteins, oxidizers, etc.) or physical (knife-trimming, cold or hot water, vacuum, and/or steam) agents and combinations of two or more agents simultaneously or in sequence are applied as carcass decontamination/sanitization treatments in the United States. Acidic decontamination of meat may lead to changes in the dominating microbial association and if combined with long-term storage may lead to development of yeasts. The microbial associations developing on muscle tissues stored aerobically at cold temperatures are characterized by an oxidative metabolism. The contribution of specific nutrients to bacterial behavior has been shown in single-culture or coculture studies. Glucose is the preferred energy substrate and the first to be used by various microorganisms growing on muscle foods. Glycolytic enzymes indigenous to muscle tissues participate in the postmortem glycolysis that ceases when the ultimate postmortem pH reaches 5.4 to 5.5. Freshness and safety of muscle food products are generally considered the most important contributors to quality.