FISH PROCESSING

fish preservation

extending shelf life of fish and other fishery products by applying the principles of chemistry, engineering and other branches of science in order to improve the quality of the products

important reasons for preserving food

• to take care of excess produce

• so that capture will reach other areas

• makes transportation and storage easier

• preserving foods at home

typical steps on handling

1. transferring the catch from the fishing gear to the fishing vessel

• upon capture, fish should be transferred from the fishing gear to fishing vessel asap

• ung capture (fish) = alive and tends to move kasi gusto nila makawala

• gear = made up of mesh or nets

  • can damage or harm the fish kaya dapat ma transfer agad

2. holding the catch before further handling

3. sorting and grading

4. bleeding, gutting, washing

5. chilling

6. storing the chilled fish

7. unloading/landing the fish when the fishing vessel returns to the port

proper techniques of handling fish

1. Avoid exposing the fish to sunlight, and keep them in a shade area.

2. Ice the fish immediately after they are caught to lower their temperature

3. Remove the gills and internal organs

4. Avoid soaking the fish too long in the water after death as this easily spoils the fish

5. Use mechanical refrigeration if there are facilities

methods of fish preservation

1. Dehydration (to control water activity)

2. Lowering Temperature (to control microbial loads)

3. Increasing Temperature (to control microbial loads)

4. Using preservatives/acids (to chemically control microbial loads)

5. Vacuum Packing (oxygen deprivation)

dehydration

to control water activity in the fish

lowering temperature

• effective method of preserving the freshness of fish is to chill with ice by distributing ice uniformly around fish

• safe cooling method that keeps fishes moist and in easily stored forms for transport

• became widely used since the development of mechanical refrigeration

  • makes ice easy and cheap to produce

• ice - produced in various shapes

1. crushed/ice flakes

2. plates

3. tubes & blocks

   1. commonly used to cool fish

• particularly effective is slurry ice

  • made from micro crystals of ice forms & suspended within a solution and a freezing point depressant (like common salt)

increasing temperature

1. Smoking and roasting

2. hot smoking

3. Long smoking

smoking and roasting

• for consumption either directly or within 12 hrs after curing

• re-smoking - can keep products in good conditions for further 12 hrs

fresh unsalted fish - put over wood or coconut husk fi

hot smoking

• used for immediate consumption or keeping the fish for a max. of 48 hrs

• after salting, they are put on iron spits and dried in a windy place or sun for another half hour

• necessary to have an oil drum to make the smoking stove

long smoking

• used when fish is kept for longer durations like 2-3 months

• can be done by smoking

• small closed shed made of palm leaves or other local mats can be used

using preservatives and acids

1. salt

   1. wet salting

   2. dry salting

wet salting

• cheaper and requires less amounts of salt

• principle is to keep fish for a very long period in brine

• salt is coarse - should be pounded or grounded first

• dissolved into water by stirring with a piece of wood

  • to be good = fish should float

dry salting

• fish is salted but juices, slime, brine are allowed to flow away

• can be done in an old canoe, mats, leaves, boxes, etc.

• brine formed by fish juices & salt should be allowed to run away

• layers of fish must be separated by layers of salt

vacuum packing (oxygen deprivation)

ex: fish canning

fish canning

• process involving heat treatment of fish in sealed containers made of tin plates, aluminum cans or glass, until product is fully sterilized

• canned fish is also prevented from contamination by storing them in virtually airtight containers

• heat treatment is done properly = canned fish can be stored up to several years without refrigeration

fish spoilage

• defined as a change in fish or fish products that renders them less acceptable for human consumption

signs of fish spoilage

1. slime formation

2. discoloration

3. changes in texture

4. off-odors

5. off-flavors

6. gas production

factors that affect spoilage and deterioration

1. microbial spoilage

2. chemical spoilage

3. autolytic spoilage

factors that influence rate of fish spoilage

1. effects of time/temperature conditions on microbial growth

2. effects of hygiene on fish quality during handling

3. method of capture and storage

market forms of fish

1. whole fish

2. drawn fish

3. dressed fish

4. pan dressed fish

5. filleted fish

6. fish steaks

7. fish sticks

8. fish cakes

whole fish

came fresh from water; no physical processing

drawn fish

fish that is eviscerated and internal organs is removed, still has scales

dressed fish

scaled and eviscerated; ready to cook

pan dressed fish

dressed fish that had its head, tail, fins removed to fit the pan

filleted fish

• fleshy sides of fish cut lengthwise from the fish along the backbone

• usually boneless, but in some fishes small bones may be present (“pins”)

• skin may be present on one side

fish steaks

• large dressed fish that can be cut into cross section slices

  • usually half to one inch thick

  • usually comes with a cross section of the backbone

fish sticks

• pieces of fish cut from blocks of frozen fillets into portions at least ⅜-inch thick

• available in fried form ready to heat or frozen raw

• coated with batter and breaded, and is ready to be cooked

fish cakes

• prepared from flaxseed fish, potatoes, and seasonings

• shaped into cakes, coated with batter, breaded, & packed and frozen

• ready to be cooked

bangus

• national fish of the Philippines; “milkfish” in English

• adaptable, tough, and sturdy fish that survives in confined spaces

  • regularly bred in fish farms

  • also the reason why it is widely available all over Philippines

• flavor = distinctive and mild

  • best paired with complementary ingredients

• usually cooked in soups, fried, grilled, barbecued, stuffed, stewed in many spices, ginger and vinegar

parts of bangus

steps in bangus deboning

1. scaling the fish

2. cutting of fins

3. cutting the fish with a butterfly cut

4. removing of entrails and gills

5. removing of backbone

6. deboning the dorsal muscle

7. deboning the ventral and lateral muscles

8. removing the rib bones

9. cleaning the fish

materials needed in bangus deboning

1. bangus (malamang bruh)

2. basin or tray

3. knife

4. chopping board

5. mosquito forceps

6. big tweezers

scaling the fish

• make sure the fish is not fresh since itll be soft

• use a knife so the fish will not be wounded and hold it straight, not in an angle and scale the fish with the dull part

• rinse with water so excess scales will be removed and the fish will be clean

cutting of fins

remove the dorsal fin, then pelvic and anal fins, then pectoral fins, and lastly caudal fins (buntot)

cutting the fish with a butterfly cut

butterfly cut- cutting open like a book

removing of entrails and guts

1. make sure that you will not damage the small dark rim part of the fish

   1. will cause the fish to taste bitter

removing of the backbone

removal of the spine/backbone of the fish

deboning - removing from dorsal muscle

with mosquito forceps - turn forceps clockwise to remove from dorsal muscle

deboning - removing from ventral and lateral muscles

with mosquito forceps - turn forceps clockwise to seperate ventral and lateral

deboning - removing from the rib bones

bones are bigger kaya mas madali matanggal, you can debone with just your hands

wash the fish

washing the finished products of the deboning

steps in filleting a small fish

1. Cut off the head just behind the gills.

2. Hold the fish by the tail. With the knife blade pointing away from you and across the body of the fish, begin to cut toward the head (or at least where the head used to be). Use the backbone to guide your knife.

3. To take the skin off, begin by holding the fillet by the tail, skin side down. 

4. Hold the knife crosswise across the fillet and insert the knife between the skin and the flesh. Don't worry if you don't get this perfect at first.

5. While holding the skin, cut in the direction of where the head used to be.

steps in filleting a large fish

1. Make a deep cut just behind the gills (about halfway through the thickness of the fish).

2. Cut a slit a few inches in length along the top of the fish (the dorsal side).

3. Using the tip of the knife, separate the flesh from the bones, as illustrated. The fish should open up just like a book.

4. When completely open, finish cutting away the fillet by moving the knife along the "spine of the book."