Fish preservation

Source: Wikipedia, the free encyclopedia.
"Preserved fish" redirects here. For the American merchant, see
fish conservation
.
Tyritake, Crimea
A fish-drying rack in Norway

Fish preservation is the method of increasing the

canning
have taken on a large importance.

Fish curing includes and of curing

anchovies are small fish of the herring family, often salted and smoked and then preserved in oil. Fish are dried under controlled conditions of temperature, humidity, and air velocity
. Since the dried product is relatively unappetizing and rehydrating slow, other preservation methods are common.

History

Socio-economic value of fish preservation

Preservation of marine products is of great importance to the coastal poor. Preserved fish products endure adequate protein during low fishing periods. Subsistence fishers use their abundant catch of small fish to make fermented fish paste and smoked fish with the assistance of family members. Large fish are used to make fermented fish or salt dried fish. Other important processing activities include drying of small shrimp, squid, ray and shark and preparation of shrimp paste.[3]

In the past, fishing vessels were restricted in range by the simple consideration that the catch must be returned to port before it spoils and becomes worthless. The development of refrigeration and freezing technologies transformed the commercial fishing industry: fishing vessels could be larger, spending more time away from port and therefore accessing fish stocks at a much greater distance. Refrigeration and freezing also allow the catch to be distributed to markets further inland, reaching customers who previously would have had access only to dried or salted sea fish.

canned sardines
.

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.[4] 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.[5]

Control of temperature

Ice preserves fish and extends shelf life by lowering the temperature
See also:
Freezing (food)

If the temperature is decreased, the metabolic activity in the fish from

autolytic processes can be reduced or stopped. This is achieved by refrigeration where the temperature is dropped to about 0 °C, or freezing where the temperature is dropped below -18 °C. On fishing vessels, the fish are refrigerated mechanically by circulating cold air or by packing the fish in boxes with ice. Forage fish, which are often caught in large numbers, are usually chilled with refrigerated or chilled seawater. Once chilled or frozen, the fish need further cooling to maintain the low temperature. There are key issues with fish cold store design and management, such as how large and energy efficient they are, and the way they are insulated and palletized.[5]

An effective method of preserving the freshness of fish is to chill with ice by distributing ice uniformly around the fish. It is a safe cooling method that keeps the fish moist and in an easily stored form suitable for transport. It has become widely used since the development of mechanical refrigeration, which makes ice easy and cheap to produce. Ice is produced in various shapes; crushed ice and ice flakes, plates, tubes and blocks are commonly used to cool fish.[6] Particularly effective is slurry ice, made from microcrystals of ice formed and suspended within a solution of water and a freezing point depressant, such as common salt.[7]

A more recent development is

HACCP and ISO food safety and public health standards, and uses less energy than conventional freshwater solid ice technologies.[8][9]

  • Fish packed in ice
    Fish packed in ice
  • Fish chilling with slurry ice.
    Fish chilling with slurry ice.
  • Fish cooling by pumpable ice
    Fish cooling by
    pumpable ice
  • Loading blocks of factory-made ice from a truck to an "ice depot" boat
    Loading blocks of factory-made ice from a truck to an "ice depot" boat
  • Ice manufactured in this ice house is delivered down the Archimedes screw into the ice hold on the boat, Pittenweem
    Ice manufactured in this ice house is delivered down the Archimedes screw into the ice hold on the boat, Pittenweem

Control of water activity

See also: Dried fish, Salted fish, Smoked fish, and Boiled fish

The

freeze-drying, water-binding humectants, and fully automated equipment with temperature and humidity control have been added. Often a combination of these techniques is used.[5]

  • Women drying fish in Indonesia, 1971
    Women drying fish in Indonesia, 1971
  • Dry fish market at Mohanganj
    Dry fish market at
    Mohanganj
  • Drying stockfish in Iceland
    Drying stockfish in Iceland
  • Fish barn with fish drying in the sun – Van Gogh 1882.
    Fish barn with fish drying in the sun –
    Van Gogh
    1882.
  • Platforms, called fish flakes, where cod dry in the sun before being packed in salt
    Platforms, called fish flakes, where cod dry in the sun before being packed in salt
  • Remains of Roman fish-salting plant at Neapolis
    Remains of Roman fish-salting plant at Neapolis
  • Reconstruction of the Roman fish-salting plant at Neapolis
    Reconstruction of the Roman fish-salting plant at Neapolis
  • Drying salted fish at Malpe Harbour
    Drying salted fish at Malpe Harbour
  • Salt fish dip at Jakarta
    Salt fish dip at Jakarta
  • Ruins of the Port Eynon Salt House – seawater was boiled to extract salt for preserving fish
    Ruins of the Port Eynon Salt House – seawater was boiled to extract salt for preserving fish

Physical control of microbial loads

See also:
Fish canning

Heat or ionizing irradiation can be used to kill the

retortable pouches before the heat treatment.[5]

Chemical control of microbial loads

See also: Biopreservation and Fermented fish

Microbial growth and proliferation can be inhibited by a technique called

benzoates and essential oils.[5]

Control of the oxygen reduction potential

Spoilage bacteria and

vacuum packaging. Controlled or modified atmospheres have specific combinations of oxygen, carbon dioxide and nitrogen, and the method is often combined with refrigeration for more effective fish preservation.[5]

Combined techniques

See also: Hurdle technology

Two or more of these techniques are often combined. This can improve preservation and reduce unwanted side effects such as the denaturation of nutrients by severe heat treatments. Common combinations are salting/drying, salting/marinating, salting/smoking, drying/smoking, pasteurization/refrigeration and controlled atmosphere/refrigeration.[5] Other process combinations are currently being developed along the multiple hurdle theory.[11]

  • Making fish paste in Cambodia
    Making fish paste in Cambodia

See:

See also

References

  1. ^ M.N., Moorjani (1998). Fish Processing in India. New Delhi: ICAR.
  2. ^ Charls L., Cutting (2002). Fish Processing and Preservation.
  3. ISBN 9789264037762
    .
  4. ISBN 92-5-103507-5
    .
  5. ^ a b c d e f g FAO: Preservation techniques Fisheries and aquaculture department, Rome. Updated 27 May 2005. Retrieved 14 March 2011.
  6. ^ FAO: Handling of fish and fish products Fisheries and aquaculture department, Rome. Updated 27 May 2005. Retrieved 22 July 2012.
  7. ISBN 978-2-913149-42-7
    .
  8. ^ "Deepchill™ Variable-State Ice in a Poultry Processing Plant in Korea". Archived from the original on February 6, 2012. Retrieved December 4, 2010.
  9. ^ "Results of Liquid Ice Trails aboard Challenge II" (PDF). April 27, 2003. Archived from the original (PDF) on January 29, 2016. Retrieved December 4, 2010.
  10. ISBN 978-84-611-9423-0
    .
  11. ISBN 978-0-306-47263-3
    .
Retrieved from "https://en.wikipedia.org/w/index.php?title=Fish_preservation&oldid=1165932910"