POST HARVEST HANDLING OF FISH

POST HARVEST HANDLING OF FISH

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Fish is one of the most perishable commodities. There is a considerableh wastage that occur after capture. The need for proper handling and processing of fish is important both for the fishing industry and for the consumers. Post-harvest fish loss (PHFL) refers to fish that is either discarded or sold at a relatively low price because of quality deterioration. Small-scale fishermen are the major ones to face problems in handling, transporting and marketing fresh fish under difficult conditions such as at high ambient temperatures. The absence of adequate facilities both on fishing craft and ashore prevents the distribution of good quality fish. As a result, microbial spoilage and contamination by pathogenic bacteria occur. This can have important implications for the export trade, especially as more stringent international quality parameters are applied worldwide.

Sri Lankans are a fish-eating community. More than 70% of the population are village-based. Most do not own refrigerators. They depend on cycle fish traders for their daily fish supply. The traders usually cut the fish according to consumers’ requirements. They resort to credit sales to maintain good relations with consumers. Also due to development of the country, people now tends to move for buying fish from fish stores in towns as well as fish boards in village fairs and now even from supermarkets.

Fish losses caused by spoilage are estimated at 10 to 12 million tons per year, accounting for around 10 percent of the total production from capture fisheries and aquaculture. Chemical deterioration and microbial spoilage are responsible for loss of 25% of gross primary agricultural and fishery products every year. Spoilage is affected by many factors; high moisture, high fat and protein content, high ambient temperature, unhygienic handling and time. These factors contribute to the occurrence of spoilage which is caused by three mechanisms: autolytic enzymatic spoilage, oxidative spoilage and microbial spoilage. During these mechanisms many compounds are produced which is responsible for spoilage

Post-Harvest losses of fish

During fishing

● Use of destructive/harmful methods of fishing. Ex: Dynamite and carbide

● Falling from the net or discarded as bycatch

● Setting fishing gear for long periods, causing fish to spoil.

● Poor hygienic practices of fishermen

During unloading

● Poor hygienic practices causing contamination

● Fish falling from basket on to the shore

● Theft at the landing site during offloading of fish

Holding fish on board

● Delay returning to landing after fishing and exposure of fish to high temperature at sea.

● Failure to gut (when practically feasible), wash and chill the fish on board

● Stepping on fish, causing physical damage

Fresh fish marketing

● Inadequate application of ice, and no insulated container used

● No access to or lack of marketing information, with oversupply of market.

● Deliberate delay in purchasing the fish by traders

During processing and packaging

● Processing of already spoiled/poor-quality fish

● Processing fish under unhygienic conditions, allowing blowfly infestation

● Drying fish unsupervised, on ground, rocks or herbs

● Breakage or damage owing to inadequate packaging method and materials.

● Oxidation of fatty fish leading to rancidity

During storage

● Growth of mold causes spoilage and makes the fish damp

● Insects consume fish during storage

● Discoloration owing to chemical changes

● Inadequate storage facilities

● Damage to fish during transportation

During marketing

● Delays in selling

● Inadequate cold-storage facilities and warehouses and lack of ice

● Supplying the market at the “wrong time”

● Poor purchasing power of buyers/consumers

The quality of fish depends on how it is handled from the time it is taken out from the water until it reaches the kitchen. To reduce losses

Handling

● Work on fish as quickly as and as promptly as possible.

● Sort fish properly before packing. According to size pack separately as possible.

● When fish have to wait on deck cover them to protect them from heat and other elements.

● Drain fish before icing

● Avoid brushing the fish

● Don’t throw, trample or kick the fish

Cooling:

● Use plenty of ice. Put additional layer of ice on top, bottom and side of fish in boxes or shelves

● Don’t over-fill a box or shelf. The next box or shelf on top will smash the fish below.

● Lay the fish belly downward – this prevents entry of dirt water into the fish.

● Don’t pack fish so tightly that melted ice cannot flow.

● Fish is cooled more quickly when ice cold water is poured on them. Fish spoils easily when allowed to stay in stagnant water, blood or slime.

● Store fish in ice as quickly as possible. Make sure the fish room is always kept clean.

Icing practices

Ice has to be used properly for it to be effective. If it is in big blocks it must be crushed into small pieces in a clean environment so that it can chill the fish to quickly retard microbial growth. Some ice is made as small pieces such as flack ice. This ice cools fish on surface. Accurate ratio of ice : fish is 1Kg ice: 1Kg fish. Ice melts as time goes on and more ice needs to be added to keep the fish cool. Ice should be made from clean water and should not be contaminated after it is made.

Ice lasts longer and chill fish better if it is used with clean insulated box. The right amount of ice needs to be used and the boxes should not be over-filled. Over-filling can crush the fish. When icing, a layer of ice has to be placed on the bottom of the box, then a layer of fish and then another layer of ice and so on.

● Vehicles/boats and engines should be regularly maintained

● Equipment and boats should be washed after use, using clean water and disinfectant.

● Fishermen must be clean and treat the fish well.

● Fish should be kept in clean, well maintained and easy to clean containers.

● If no ice, try evaporative cooling methods.