1. Fish Processing Presented by Aditya Parmar Food Safety and Quality Chains UniHohenheim
2. ContentsIndustry SenarioDecomposition ProcessPreservation ProcessTake Home Messages
3. HistoryA medieval view of fishprocessing, by Peter Brueghel theElder (1556). Source: Wikipedia Fishermen and sea creatures, mosaic, 1st century AD Copyright 2004 Bridgeman
4. World Fish ProductionIndia has a coastline of more than 7,000 km. The total navigable length of inland waterways is 14,500 km.
5. Per Capita Consumption 5kg
6. Industry SenarioSource: FishStat FAOThe bulk of the catch comprises oil sardines, followed by penaeidand non-penaeid shrimp, Indian mackerel, Bombay duck, croakers,smaller quantities of cephalopods, other sardines and threadfinbreams.(CMFRI 2008).
7. World ComparisionSource: DAHD&F 2005 Source: Wikipedia India reprents about 5-6 % of the world fishing production
8. World TradeThe share of Indian fish exports in world trade isonly about 6.5%. This invites urgent steps toincrease the share from India.
9. Domestic DemandThe projected demand for fish in the country by 2012 is 9.74 million tons,which can be met by the projected supply of fish of 9.60 million tons by 2012
10. Composition 65-80% Water Sea Food is Highgly perishable due to: 1-20% Fats 1. High moisture content . 2. Avialability of nutrients for the growth of micro Protien organisms. 14-20% 3. Ambient temperature.VitaminsMinerals
11. Fatty and White Fish
12. DecompositionSpoilage Indications: Enzymatic1. Change in colour.2. Odour, texture.3. Colour of eyes.4. Colour of gills.5. Softness of the muscle. Oxidative Bacterial
13. Enzymatic spoilage1. After the death, the normal circulatory system breaks down and chemicalsignals leak into the muscle causing them to stiffen. This process is known asRigor Mortis.2. The blood circulation stops and the supply of oxygen is prevented. Theenzymes present in the muscle convert glycogen into lactic acid. The pH of thefish muscle falls.3. After the completion of rigor mortis, muscle stiffness gradually decreasesaccompanied by increase in pH, ending up in softening of muscle. This isfollowed by breakdown of proteins by enzymes. This process is called asautolysis. Autolysis of protein starts immediately after rigor and createsfavourable conditions for the growth of bacteria.4. ATP to AMP and Hypoxanthine. Thus the estimation of Hypoxanthine contentin fish indicates the degree of freshness.5. Enzymatic action also causes decomposition in the fish known as bellybursting.
14. Oxidative Deterioration The most common chemical action which causes spoilage is the oxidative rancidity in fatty fishes. The levels of peroxide value and free fatty acid content both a measure of oxidative rancidity are considered an index of quality of fat fishes.Oil Mainly TriglyceridesTriglycerides Free Fatty Acids Peroxides, Ketones andAldehydesOxidation results in:1. Rancid Odors2. Colour Changes
15. Bacterial SpoilageReduction of TMAO to TMAOdourless TMAO which is reduced to an offensive smelling TMA.Breakdown of Amino Acids and formation of Primary AminesExamples are formation of histamine from histidine, arginine fromglutamic acid etc. This bacterial action may cause food poisoning inextreme cases.Breakdown in UreaThe high concentration of urea in the flesh of some fishes is degradedto ammonia by the microorganisms. The formation of ammonia isaccompanied by an offensive odour.
16. Decomposition ProcessesDeterioration processes in fish Lipids Proteins Chemical, bacterial and endogeneous enzyme reactionsOxidation of fatty acids Hydrolysation of proteins to peptides andHydrolysation of lipids to free fatty acids amino acids Deamination of amino acids Decarboxylation of amino acids
17. So, the answer is - Preservation
18. 1. Temperature controlPrinciple - Decrease the fish temperature to levels where metabolicactivities are reduced or completely stopped (0 C or < - 18 C) .1. The design (size, insulation, palletization) and management ofcold stores are key for fish quality and energy saving.2. Development of alternative refrigerants to replace thechlorofluorocarbons (CFCs) which are damaging to ozone layers.
19. 2. Control of water activity Water activity (aw) is a parameter that measures the availability of water in fish flesh. Water is necessary for microbial and enzymatic reactions and several preservation techniques have been developed to tie up this water (or remove it) and thus reduce the aw. 1. Drying 2. Salting 3. Smoking 4.Freeze-dryinghttp://www.aqualab.com
20. 3. Physical controlUse of heat (cooking, blanching, pasteurizing, sterilizing), ionizingirradiation (for pasteurization or sterilization) or microwaveheating.Refrigeration is required to preserve fish products and increase theirshelf life.Sterilised products and which are stable at ambient temperatures (