Download - Preparation of Fish Fillet Blocks
MFR PAPER 1277
Preparation of Fish Fillet Blocks
JOHN J. RYAN
BACKGROUNDFrozen fish fillet blocks are used as
the raw material in the manufacture offish sticks and portions and other specialty items.
In 1976, nearly 400 million poundsof blocks were used for this purpose inthe United States. Imports accountedfor 379 million pounds with domesticproduction adding less than 0.6 percentto the total. Cod and pollock are theprincipal species used for makingblocks. Iceland was the principalsupplier followed by the Republic ofKorea, Canada, Denmark, Norway,and Japan. Cod accounted for 48 percent of the total followed by pollockwhich accounted for 25 percent. Codblocks were supplied by Denmark, Iceland, Canada, and Norway. Pollockblocks were supplied by the Republic ofKorea with 61 percent of the total followed by Japan's 11 percent.
FirSI cuI behind fin.
Remove nape area offillet from collar bone.
John J. Ryan is with the GloucesterLaboratory, Northeast FisheriesCenter, National Marine FisheriesService, NOAA, Emerson Avenue,Gloucester. MA 01930.
January 1978
Medium-sized eviscerated cod.
Cut along dorsal fin (close to thebackbone) toward tail.
Additional sizes and shapes having limited use are as follows:
Dimensions(inches)
2 J x I I 1f2 X 11/219 x 10 x 2Vz19 X (IYa x 21f224 X 191/2 x 3
DimenSIOns(inches)
13xllVzxllla17\4 x 111-4 x 1%21 x 101f2 x JI/217 X 111f2 x Ilia20 x 11% x 1%20 x (( % X I1f216 X 11 1/16 x 2Ya19 x 10 x 2%(8l1a x 10 x 2.421 x 113/8 x 2%
Weight(pounds)
10IIJ2V213 \4131f213Vz15161/2
161/2
171f2
Weight(pounds)
J 31/2
161f218 1/2
491f2
Because fish sticks and portions arecut to specified dimensions and a specified number are placed in a package toarrive at a definite weight, it is important that the frozen block of fillets be of
At left, filleting: Reverse knife alongbackbone. Bottom left, remove fillet fromfish. Below, skin fillet.
PROCESSING METHODS
A fish fillet block is a uniform, cohering mass of usually skinless fillets frozen together under pressure. Becausefish sticks and portions are cut todefinite dimensions and weights, different sizes and shapes of fish filletblocks are produced. The principalsizes and shapes of fish blocks beingutilized in this country are as follows:
6 Marine Fisheries Review
a uniform density. Generally, an acceptable block will not vary more thanl/S inch in any dimension from thosespecified.
A typical method of preparing fishfillet blocks will be used as an example.Essentially, boneless and skinlessfillets are carefully placed into a waxed,one-piece folding carton either parallelwith or perpendicular to the long axis ofthe box. In both cases, the thick portionof the fillet is placed adjacent to an edgeof the container, and the thin portion isplaced into the middle. The depressionso formed is built up with fillets untilthe desired weight is obtained. The containers are slightly overfilled with fishso that all surfaces are uniformly filledwith every effort being made to avoidsloping surfaces, bad corners, orvoids.
For freezing, the blocks are put into awooden or metal tray and then placedinto a multiplate compression freezer.Space sticks of the correct size are usedto prevent deformation or bulgingcaused by excessive pressure duringplate freezing. Freezing time should notexceed 3 hours, and the internal temperature of the product should be reduced to at least -50 0 F at the thennalcenter after thermal stabilization. Usingthe correct sized spacers, slightly smaller in depth than the containers, causesa very slight compression of the containers when the plates are lowered.This compression smooths out the surface of the fish. Finally, when all thecontainer is filled with fish flesh, thecompression forces the fillets to fusetogether into a single block of fish.
Upon removal of the blocks from theplate freezer, the blocks are taken out ofthe tray and packed into a corrugatedmaster container. Usually, four blocksare packed into a corrugated mastercontainer.
The series of photographs in thispaper depicts the many steps involvedin making a good quality block. Theypoint out many of the details that go intoblock production that would be difficult to describe with words.
LITERATURE CITEDAnonymous. 1977. Fisheries of the United
States, t976. U.S. Dep. Commer., NOAA,Natl. Mar. Fish. Serv., Curr. Fish. Stat. 7200,96 p.
January 1978
First cuI to remove pin bones.
Second cut to remove pin bones.
Bones removed.
7
Counterclockwise from top:Removing black membrane; skinlessand boneless fillet; cut thickest part offillet on angle to permit betterpacking; and cut fillets in half.
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Counterclockwise from top: Blockpan for 16\7-pound block doubledwith removable divider; unfoldedblock carton; folded block canon withall tabs overlapping on outside toprevent imbedded tabs; and square cutfillets bUlled into comer of carton.
January 1978 9
Packing fillets into carton, all corners filled first.
Completely filled carton. Top surfaces should be flattened and leveled.
Partially filled carton. Long fillets should always be cuI in half.
Close carton. Overlapping cover edge is placed outside to prevent imbedding in block.
Finished carton. Top surface being smoothed.
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Counlerclockwise from top: Blockcanons ready for plate freezing; platefreezer with piales up; plate freezerwith blocks and plates compressed;and removing blocks from platefreezer.
January 1978 11
Frozen block with square side andcorners and absence of voids.
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frozen block side view.
MFR Paper 1277. From Marine Fisheries Review, Vol. 40. No.1, January 1978.Copies of this paper, in limited numbers, are available from 0822, User Services Branch, Environmental Science Information Center, NOAA, Rockville.MD 20852. Copies of Marine Fisheries Review are available from the Superintendent of Documents, U.S. Government Printing Office, Washington, DC20402 for $1.10 each.
Marine Fisheries Review