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United states Department of the Interior Fish and Wildlife Service

Fishery Leaflet 120 il Chicago 54, Ill. April 1945

ehydration of Fishery. Products

By Maurice E. Stansby T echllologist in Cha.rgc Fishery Technological Laboratory Fish & Wildlife Service S mttlc, Wash ington

investigation of this subject at its Fisheries Technological Laboratories in both Col­ lege Park, Md., and Seattle, \Nash. The work in the Seattle Laboratory was pri­ marily on engineering studies to determine the best processing technique anel to learn the effect of various processing' methods upon storage life of the product. The College Park Laboratory concen­ trated mainly on the utility of different species for dehydration. the determination of the nutritive value of the dehydrated product, and the application of several new and unusual processing methods to the dehydration of fi sh. Processinq Experimental fish dehydrator used by Seattle Fishery Technological Laboratory. F.ngineering studies on processing were ESTS conducted by the Techno­ In 1942 when shipping space was at a carried out in a horizontal tunnel drier logical Laboratories of the U. S. great premium, considerable interest was (see Figure 1) in which temperature and T Fish and Wildlife Servic indicate displayed by various governmental food relative humidity were automatically con­ that dehydration of fish is a relatively purchasing agencies in dehydrated prod­ trolled and air velocity could be v

(Beprintecl from the Annual Review Number of FiShing Gazette, 1944. p. 182). Tests at Colleee Park, Maryland. {,aboratory. scales \Vas con id e red necessary to obtain a product of acceptable consumer stand­ ard. In most cases bone . free fillets \I ere used in the experimental work. In order to obtain a sati factory rate lIf drying. pre coo ~il} g was fou nd to be necl"'~ 'ia ry. Ra\l' fisl ~ ot on ly drIed at a rate 01 about one-third tl'at of couked fish. but a ls o. the resulting pnlduct did not rehy­ drate as \\·el1. absllrhing Ie" than hali a ' much water as did the .product obtained from cooked fi,h . .- \ cnoking time of 7 to 10 minutes at ~ tll 10 pound !'team pre - sure ,vas found tll give lI ptimum drying and rehydration. ~o extensive expenml"nts \Inc tried on dehytlration of \\hole fish Ilr fillets ,mce prelimlllary n·,ulh sho\\ ed that unless the fish were ground after r!loking. re­ moval of \later '" a - slo\\" and IIIcompletl. In (lrder to remove moisture at a rate sufficiently rapid fur commercial npera­ tilln . preliminary grinding \\as essential. .\ rather \\idc range of cllnditiollS wcre found to be 'iuItable for ,atisfactury dehy­ dration of fish. Drying temperatures as nigh as 205 0 F. can be used in the initial cod. mullet, whiting and carp were con­ process utilizi ng radio frequency energy any sort of reasonable storage life, it is ducted and it wa found that the dehydra­ as a so urce of heat. and the process em­ nece sary to reduce the moisture content tion proce did not adver ely affect either plnying high vacuum desiccation of the to well below 5 per cent and to store in a the nutriti"e value nor the digestibility. in zen product \\'ere tried in a preliminary hermetically sealed container (such as a Tl·,;t - on the thiamine (vitamin B.) and \Vay. Both of these processes showed till can) either in a vacuum or with an nboHavin (vitamin B,) content before and promise but since neither of these methods inert gas such as nitrogen. Even under after dehydration howed that the dehy­ are. as yet. sufficiently perfected for com­ the,l conditions the product definitely de­ dratIOn proce s cau ed a 10 of about 50 mercial adaptation to dehydration of fish. teriorates in a six-month period of time. pl r cent of the thiamllle and 6S per cent no extended studIes \\ere made. Storage changes occurring with non­ of the riboflavin. The 10 took place Species \\'hich have been successfully oily species include development of an largely in the cooking proce - and about dehydrated include cod. whiting. ra jafish, extremely tough texture, darkening of half of each vitamin los could be recov­ angler fish. sea robins, pu ff ers, croakers. cuIo r, and appearance of a burnt flavor ered in the tickwater. ling, mullet. groupers, sea trout. and se<1 and odor. These changes are identical mussels from the Atlantic Coast; carp with tho e encountered with dehydrated Methods of Utilizing and burbot from interior waters ; and rock eggs where such changes are attributed Dehydrated Fish cod. grey cod, halibut, herring, pilchard, to a chemical combination between the The dehydrated fish products are readily petrale sole, ch um salmon. king salmon, protein and certain sugars which occur in rehydrated by mixing four to six parts br2J silver salmon, Pacific mackerel, and squid only small traces in eggs. With dehy­ weight cold water with one part of the from the Pacific Coast. drated eggs these changes are minimized dehydrated product and allowing to stand

Y Ea.. fish required three times as long a. drying time as cooked fish. 2J '!his gives an excess of water which must be drained after rehydra.tion is complete.

2 for .15 to 30 minut s. Shaddock fi llets as 30 cent per ppund, and if we reduce the water content from 80 per cent to 1 per Grinding fish, preparatory to dehydration. cent, then the finished product will have been concentrated five times and the raw material cost exclusive of all processing and overhead charges will be $1.50 per trash fi sh as are at pre ent not utilized at government and, 0 far as i. known, this pound. It is hard for the ultimate con­ all. If small fi sh like pilchard were to be i the only plant operatinl{ in thi country. sumer to realize he is buying such a con­ dehydrated, the labor cost of dre ing and American governmcntal al{enci are centrated foodstuff, and he is usually preparation would be so high when trans­ howing no int('rest at pre 'ent in ither unwilling to pay such a high price for a lated to the cost of the concentrated final meat or fi . h. \ ccordlllgly. at the pre nt cw product with which he is unfamiliar. product a to eriously limit even the pos- time the outlook for de\' lopmcnl of a le e considerations limit the possibility ibility of utilizing such fi h in this way. dehydrated fi . h llldu~try, either for foreign or rehydrated fish production to such t the present time, one ea t coa t plant or dome tic markeL, i not vcry promis­ inexpensive species as pilchard or to such is preparing dehydrated fi . h for the British ing.

REFERENCE S

Ano~us. 1943. Dehydrated B. C. fish found to make attractive food products. Commercial Fishermen's weekly, vol. 9, no. 32, pp. 375-376, October 15. 1943. Dehydration of fish. Fishing Gazette, vol. 60, no. 9, pp. 34-35. Septembu. 1943. Dehydration through electronics. Quick Frozen Foods and the Locker Plant, vol. 6, no.2. September. 1944. Commercial herring dehydration. Food Manufacture, vol. 19, no. 9. p . 307, September. 1944. Automatic controls for proper food dehydration. Fishing Gazette, vol. 61. no. 3. March. 1945. New products from IIIUllet. Southern Fisherman, vol. V, no. 3. p. 152, January. Birdseye. Clarence. 1944. Dehydrated foods must be good. Quick Frozen Foods ani the Locker Plant. March.

Carl. Betty C., Betty M. Watts, ani Agnes F. M:>rgan. 1944. Dehydration of meat scrapples. Food Fe search. vol. 9, DO. 4, pp. 319-327, July- st.

Co en , Camillo. 1931. Preserving fish. French Patent No. 719.525. June 15.

Cooper, D. LeB. 1937. Fish drying. Biological Board of Ce.ned.a-Progress Reports of the Atlantic Stations no. 20, pp. 8-10, August.

ting, C. L •• and G. A. Beay (Torrey Fesearch Station - lhgland). 1944. 'the dehydration of fish. Olemistry and Industry. no. 6, pp. 7-50.

3 Grelck, Y. P. M. 1935. Preparing fish or vegetable material for use as food. U. S. Patent 10. 2,009,134, July 23. I

Hamm, W. 5., C. Butler and M. Heerdt, Jr. 1944. Food fish dehydra.te well. Food Industries, June, pp. 445-447" and. 4 89-4~.

Harper, L. K. 1943. Postwar possibili ties of dehydration. Quick Frozen Foods and the Locker Plant, ~.

Loesecke, H. W. von 1943. Drying and dehydration of foods, chapter 5, pp. 16c>-177. Reinhold Publishing Corp., New York.

Martinek, Willia.m A., and Barbara Jacobs. 1943. The nutritive value of the protein of some dehydrated fishery products. Fish and Wildlife Service, Fishery Market News, vol. 5, no. 8, Separate 34.

Minde, lIjalmar. Process for manufacture of keepah1e fish products. Alien Property Chstodian Patent No. 2,7/1,7/2.

Omierei, F.Y. 1932. Apparatus for preparing powdered fish. U.S. Patent No. 1,867,523, July 12.

Patterson, James C. 1943. Food dehydration. BBfrigerating Engineering, vol. 45, no. 6, June.

Be83', G.A., and C.L. Chtting. 1943. Dehydration--fish and fish products. Department of Scientific and Industrial Re­ search, British Ministry of Food, unpublished report, pp. 1-16, June.

Scott, Geo. G., and Harold G. lIblffe. 19181 Dehydration of fish. Bureau of Fisheries Mem. s-l81.

Si la.W8\Y, E. P., and O. C. Young. 1943. An air-conditioned. tunnel for processing fish. Fishery Research Board of Cmada­ Progress Beports of the Pacific Coast Stations, no. 56, pp. 4-5, September.

Silver, J. A.. 1943. Dehydration through freezing. Quick Frozen Foods and the Locker Plant, June.

Steinherz, Dezsoe. 1943. Some experiments in low temperature dehydration. ~ick Frozen Foods and the Locker Plant, July.

Tarr, 11. L. A. 1943. Oumges in moisture, micro-organisms, and volatile bases in dehydrated fish during processing and storage. Fishery Research Board of Q3naAa.-Progress Reports of the Pacific Coast Stations, no. 57, pp. 16-2:>, December.

y 8JIIOma. to, S., and S. Masuda.. 1926. '!he chemica.l change in the heat drying of fish. Journal Imperial Insti tute (Tokyo), vol. 22, pp. 188-197 (English resume).

Young, Leo, and C. F. Lee. 1943. Dehydration of fishery products. Fishing Gazette, vol. 60, no. 13, p. 64, December. Young , O. C., and E. P. Sidaway. 1943. 'lhe dehydration of fish. Fishery Research Board of Canada-Progress Reports of the Pacific Coast Stations, no. 56, pp. 7-9, September. 1943. Dehydration of fish. Western Fisheries, vol. 'LI, pp. 8-9, December.

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