Freshness and quality are perceived differently by consumers, processors, regulatory officials, and scientists. This is particularly so with respect to seafood, the freshness and quality of which are subject to wide interpretations. Maintenance of the quality of both wild and aquacultured fish is more difficult than in the case of other muscle foods. Unlike all other major food supplies, the production of seafood cannot be directly controlled, enhanced, or accurately predicted. There is an unusual diversity in the seafood industry depending on the types of harvest, fishing techniques, types of products, production volumes, and location. In addition, the inherent nature of seafood makes them more susceptible to food-borne hazards.1,2

The quality of fishery products is influenced by both intrinsic and extrinsic factors. Species, size, sex, composition, spawning, the presence of parasites, toxins, contamination with pollutants, and cultivation conditions are the factors responsible for changes in intrinsic quality.3,4 The biochemical characteristics of fish muscle such as low collagen, comparatively higher contents of unsaturated lipids as well as soluble nitrogen compounds influence autolysis, rapid microbial proliferation, and spoilage. Fatty fish such as sardines and herrings deteriorate more quickly than lean fish. Small fish that have been feeding heavily prior to being caught may undergo tissue softening and break easily after death due to autolysis.4 Larger fish have higher marketability and value because of the higher yield of edible material and longer shelf life.