Processing of fish

Processing fish involves primarily the application of preservation techniques in order to retain quality and increase shelf life. It may also deal with value-adding to produce a wide variety of products.

 The first and most obvious handling technique for preserving the quality of fish is to keep them alive for as long as possible before cooking and consumption. This has been done for thousands of years in China for carp, using long-established techniques. Today, a large number of species are now kept alive to preserve quality prior to consumption.

A number of methods are used to preserve fish. Some employ techniques based on temperature control, using ice, refrigeration or freezing; others on the control of water activity and include drying, salting, smoking and freeze-drying. Techniques may rely on the physical control of microbial fish loads, such as through microwave heating or ionizing irradiation, or on chemical control of microbial activity and loads by adding acids, for example, to fish products. Techniques are also used that are based on oxydo-reduction, such as vacuum packaging. Most often a combination of different techniques is used to preserve fish.

Finally, fish processing operations include proper waste management techniques. The further processing of fish into a wide variety of value-added products is now common with the increase in demand for food products that are ready to eat or require little preparation before serving. For the transportation of chilled and frozen fish products by road, rail, sea or air, it is essential that the cold chain is maintained throughout. This requires the use of insulated containers or transport vehicles and adequate quantities of coolants or mechanical refrigeration. Container technology now makes possible the combination of refrigeration combined with a modified or controlled atmosphere.