Fish processing

The term fish processing refers to the processes associated with fish and fish products between the time fish are caught or harvested, and the time the final product is delivered to the customer. Although the term refers specifically to fish, in practice it is extended to cover any aquatic organisms harvested for commercial purposes, whether caught in wild fisheries or harvested from aquaculture or fish farming.Fish is a highly perishable food which needs proper handling and preservation if it is to have a long shelf life and retain a desirable quality and nutritional value. The central concern of fish processing is to prevent fish from deteriorating. The most obvious method for preserving the quality of fish is to keep them alive until they are ready for cooking and eating. For thousands of years, China achieved this through the aquaculture of carp. Other methods used to preserve fish and fish products includeWhen fish are captured or harvested for commercial purposes, they need some preprocessing so they can be delivered to the next part of the marketing chain in a fresh and undamaged condition. This means, for example, that fish caught by a fishing vessel need handling so they can be stored safely until the boat lands the fish on shore. Typical handling processes arePreservation techniques are needed to prevent fish spoilage and lengthen shelf life. They are designed to inhibit the activity of spoilage bacteria and the metabolic changes that result in the loss of fish quality. Spoilage bacteria are the specific bacteria that produce the unpleasant odours and flavours associated with spoiled fish. Fish normally host many bacteria that are not spoilage bacteria, and most of the bacteria present on spoiled fish played no role in the spoilage. To flourish, bacteria need the right temperature, sufficient water and oxygen, and surroundings that are not too acidic. Preservation techniques work by interrupting one or more of these needs. Preservation techniques can be classified as follows.Fish packed in iceFish chilling with slurry ice.Fish cooling by pumpable iceLoading blocks of factory-made ice from a truck to an 'ice depot' boatIce manufactured in this ice house is delivered down the Archimedes screw into the ice hold on the boat, PittenweemWomen drying fish, 1971Dry fish market at MohanganjDrying stockfish in IcelandFish barn with fish drying in the sun – Van Gogh 1882.Platforms, called fish flakes, where cod dry in the sun before being packed in saltRemains of Roman fish-salting plant at NeapolisReconstruction of the Roman fish-salting plant at NeapolisDrying salted fish at Malpe HarbourSalt fish dip at JakartaRuins of the Port Eynon Salt House – seawater was boiled to extract salt for preserving fish'The search for higher productivity and the increase of labor cost has driven the development of computer vision technology, electronic scales and automatic skinning and filleting machines.'Automatic knives for filleting fishPatent issued to Clarence Birdseye for the production of quick-frozen fish, 1930Processing line for fish fingersFish feed production in NorwayWaste produced during fish processing operations can be solid or liquid.Fish is transported widely in ships, and by land and air, and much fish is traded internationally. It is traded live, fresh, frozen, cured and canned. Live, fresh and frozen fish need special care.The International Organization for Standardisation, ISO, is the worldwide federation of national standards bodies. ISO defines quality as 'the totality of features and characteristics of a product or service that bear on its ability to satisfy stated or implied needs.'(ISO 8402). The quality of fish and fish products depends on safe and hygienic practices. Outbreaks of fish-borne illnesses are reduced if appropriate practices are followed when handling, manufacturing, refrigerating and transporting fish and fish products. Ensuring standards of quality and safety are high also minimizes the post-harvest losses.'HACCP is a system which identifies hazards and implements measures for their control. It was first developed in 1960 by NASA to ensure food safety for the manned space program. The main objectives of NASA were to prevent food safety problems and control food borne diseases. HACCP has been widely used by food industry since the late 1970 and now it is internationally recognized as the best system for ensuring food safety.Finfish, or parts of finfish, are typically presented physically for marketing in one of the following formsCutting frozen tuna with a band sawFilleting hakeJapanese utensils used to fillet large tunaFilleting soleThere is evidence humans have been processing fish since the early Holocene. For example, fishbones (c. 8140–7550 BP, uncalibrated) at Atlit-Yam, a submerged Neolithic site off Israel, have been analysed. What emerged was a picture of 'a pile of fish gutted and processed in a size-dependent manner, and then stored for future consumption or trade. This scenario suggests that technology for fish storage was already available, and that the Atlit-Yam inhabitants could enjoy the economic stability resulting from food storage and trade with mainland sites.'Egyptians bringing in fish and splitting them for saltingMedieval smokehouse at Walraversijde, ca. 1465Ice house used to preserve fish at Findhorn