4 Fish and Seafood

Spoilage starts as soon as a fish dies as a result of a complex series of chemical, physical, bacteriological, and histological changes that occur in the muscle tissue. Freezing is considered an excellent process for preserving the quality of fish for longer periods of time. Freezing and subsequent cold storage are particularly useful in making seasonal species of fish, like herring and mackerel, available all year round. Product preparation and packaging significantly affect the quality and shelf life of frozen fish. If not properly controlled, these processes result in some deleterious effects after prolonged storage. Fish and seafood can leak gases or unsightly fluids, which may have unpleasant odors. The choice of appropriate packaging materials and methods for frozen fish is a critical factor in terms of shelf-life extension. Visual examination under a transmission or scanning electron microscope is a powerful technique used in the determination of textural changes in fish muscle due to denaturation.