Nothing Special   »   [go: up one dir, main page]
Scribd Logo
Upload

Welcome to Scribd!

  • 485 views

    Fish Processing

    Uploaded by

    pardeep
    Fish processing and preservation methods are needed to reduce post-harvest losses of up to 35% of the global fish catch. Simple methods applied near the point of catch can help, including icing fish immediately to slow enzymatic and bacterial spoilage. Further processing methods include salting, sun drying, smoking, and canning, which inhibit bacteria through salt concentration, moisture removal, or high heat sterilization. Adopting these low-tech preservation techniques has potential to increase protein availability and nutrition in developing countries where fish losses often exceed 50% of the catch.

    Copyright:

    © All Rights Reserved
    Download as PPTX, PDF, TXT or read online from Scribd

    Fish Processing

    Uploaded by

    pardeep
    485 views21 pages
    Fish processing and preservation methods are needed to reduce post-harvest losses of up to 35% of the global fish catch. Simple methods applied near the point of catch can help, including icing fish immediately to slow enzymatic and bacterial spoilage. Further processing methods include salting, sun drying, smoking, and canning, which inhibit bacteria through salt concentration, moisture removal, or high heat sterilization. Adopting these low-tech preservation techniques has potential to increase protein availability and nutrition in developing countries where fish losses often exceed 50% of the catch.

    Original Description:

    Original Title

    Fish Processing.pptx

    Copyright

    © © All Rights Reserved

    Available Formats

    PPTX, PDF, TXT or read online from Scribd

    Did you find this document useful?

    Is this content inappropriate?

    Fish processing and preservation methods are needed to reduce post-harvest losses of up to 35% of the global fish catch. Simple methods applied near the point of catch can help, including icing fish immediately to slow enzymatic and bacterial spoilage. Further processing methods include salting, sun drying, smoking, and canning, which inhibit bacteria through salt concentration, moisture removal, or high heat sterilization. Adopting these low-tech preservation techniques has potential to increase protein availability and nutrition in developing countries where fish losses often exceed 50% of the catch.

    Copyright:

    © All Rights Reserved
    Download as PPTX, PDF, TXT or read online from Scribd
    Download as pptx, pdf, or txt
    485 views21 pages

    Fish Processing

    Uploaded by

    pardeep
    Fish processing and preservation methods are needed to reduce post-harvest losses of up to 35% of the global fish catch. Simple methods applied near the point of catch can help, including icing fish immediately to slow enzymatic and bacterial spoilage. Further processing methods include salting, sun drying, smoking, and canning, which inhibit bacteria through salt concentration, moisture removal, or high heat sterilization. Adopting these low-tech preservation techniques has potential to increase protein availability and nutrition in developing countries where fish losses often exceed 50% of the catch.

    Copyright:

    © All Rights Reserved
    Download as PPTX, PDF, TXT or read online from Scribd
    Download as pptx, pdf, or txt
    of 21

    FISH PROCESSING AND

    PRESERVATION

    BY: P.D
    INTRODUCTION

    Post harvest Losses of fish reach 35 percent, nearly 25


    million tons, of the world’s fishing catch. The FAO has
    estimated that in some developing countries, postharvest
    losses of fish exceed those of any other commodity, often
    super passing 50 percent of the landed catch. The losses
    are highest in the countries whose population have lowest
    protein intake. Reducing these losses could increase
    protein availability, improve nutritional status, and
    eliminate some of the need of import food.
    Reason for Postharvest Losses From Catch to
    Market
     The lack of appropriate methods to preserve the catch on board result in
    heavy loss.
     Additional losses occur in the period after docking and before marketing.
    During this period exposure, inadequate processing and insect infestation
    take their toll.
     Catch is further reduced by poor transport to market, unsatisfactory
    preservation and further exposure during the marketing process.

    This slide will explain various fish processing method between catch and
    marketing.
    Some technologically simple preservation and processing methods, which
    could be adopt at the village level are also described
    Enzymatic spoilage
    1. After the death, the normal circulatory break down and chemical signals leak into the
    muscles causing them into stiffen. This process is known as Rigor Mortis

    2. The blood circulation stops and the supply of oxygen is prevented. The enzymes present in
    the muscles convert glycogen into lactic acid. The pH of the muscle falls

    3. After the completion of rigor mortis, muscle stiffness gradually decrease accompanied by
    increase in pH, ending up in softening of muscles. This is followed by breakdown of
    proteins by enzymes. This process is called as autolysis. Autolysis of protein starts
    immediately after rigor and creates favorable conditions for the growth of bacteria.

    4. ATP to AMP and Hypoxanthine. Thus the estimation of Hypoxanthine content in fish
    indicate the degree of freshness
    Oxidative Deterioration

    The most common chemical action which causes spoilage is


    the oxidative rancidity in fatty fishes.
    The level of peroxide value and free fatty acid content both a
    measure of oxidative rancidity are consider an index of
    quality of fat fishes

    Oxidation results in
    1.Rancid odors
    2.Colour Changes
    Bacterial spoilage

    Breakdown in Urea
    The high concentration of urea in the flesh of some fishes is
    degraded to ammonia by the miroorganism. The formation of
    ammonia is accompanied by an offensive odour.

    Breakdown of Amino and formation of primary Amines


    Examples are formation of Histamine from histidine, arginine from
    glutamic acid etc. This bacterial may cause food poisoning in
    extream cases.
    So answer to these spoilage
    and losses are ?

    Processing and Preservation


    Primary Processing or On Board Handling
    1. Fresh fish are highly perishable and start to spoil as soon as they are landed.
    2. The first consideration should be to bring the fish aboard alive and in good
    condition.
    3. Fish should only come in contact with clean surfaces. It is important that
    bacterial contamination be kept low by keeping the deck, hold and storage
    boxes free of fish residues, dirt and slime with the use of clean seawater and
    scrubbing
    4. Fish should be handled with care. Kicking, trampling or dumping the fish
    will increase the rate of spoilage.
    5. For high quality fish should be chilled as quickly as possible to 0 degree
    Celsius. Before fish are landed, Hot decks should be cooled with clean water.
    Because high temperature is the single biggest cause of quality loss.
    6. It is most efficient to put the ice and fish together in a covered box. Flakes or
    small pieces of ice provide the most effective cooling. Large irregular pieces
    can damage the fish. Fish and ice should be packed in alternate layers.
    Dumping ice on a pile of fish will not give a good result.
    Secondary Processing

    The purpose of secondary processing is to convert the raw fish into a form that is still acceptable to the
    consumer and that has a longer shelf life. However to ensure a high quality finished product, it is necessary
    to begin with a high-quality raw product. This once again accentuates the importance of primary processes
    Steps Involved in Fish Processing
    Salting
     It is the process that has been used for thousands of years to
    preserve marine products.
     Salting has no adverse effect on the value of fish protein, Bacterial
    growth can be significantly retarded by the presence of sufficient
    quantities of common salt.
     When fish is placed in a brine solution the salt penetrates the fish
    and water is extracted from the tissue by osmosis.
     At a salt concentration of 6-10 percent in the fish, the activity of
    most bacteria that cause spoilage will be inhibited.

     Several methods of salting are commonly used: dry salting, brine


    salting, and pickle salting
    Sun Drying And Dehydration

    •Much of the fish in rural areas of the tropics is preserved by the sun
    drying.
    •Drying is the process in which moisture is removed by the exposure
    to natural air current as humidity is regulated by climatic condition

    •Dehydration is the process of removing moisture with the use of the


    mechanical device that provides artificial heat for drying.
    •Very small and thin fish can be dried straight away in the sun if they
    are brought in early enough in the morning.
    •If these conditions are not fulfilled the fish must be put for one night
    in brine or dry salted
    •They can then be dried the next morning.
    Smoking
    •Smoking is another method used to prepare fish products with long storage
    lives.
    •Smoke contains substances that kills bacteria, thus helping to preserve the
    product.
    •The heat also dries the fish. Often fish are salted before they are smoked
    •In hot smoking the temperature is long enough to eliminate the non-
    sporulating spoilage bacteria
    Canning

    1. This is very effective method though costly but product is very


    good and retains much of flavor.
    2. Fish is cleaned and then cut to proper boneless pieces in filleting
    plants.
    3. The pieces are then brined or pickled to improve taste.
    4. Preliminary cooking is then carried out.
    5. Cooked pieces are then put in canes.
    6. Final cooking combines sterilization with steam and high
    temperature at 110 degree Celsius
    7. The cans are finally sealed in canneries
    8. Keeping period depends upon the quality of raw material used as
    well as the vacuum created in the sealed cans
    Thank you For Being
    Patient with Me…….

    You might also like