s. T . I . C1,N,\11% I E FISHEIiIES RESEARCH BOARD OF CANADA N,'.,f13NA P.i_S‘"-:.,1-■ ..11 Translation Series No. 681

OTTAWA CANADA

Some aspects of the relationship between fat and water content, and fat distribution, in edible fishes

By C.-H. Brandes and R. Dietrich

FISHERIES RESBRCHEOf\RD OF CANADA Halifax Library I.REETe 1707 LOWE; , P. 0. ; ), ALIF NYAR., SCOTIA

Original title: Betrachtungen über die Beziehungen zwischen dem Fett- und Wassergehalt und die Fettverteilung bei Konsumfischen

From: Verbffentlichungen des Instituts für Meeresforschung in Bremerhaven, Vol. 5, pp. 299-305, 1958.

Translated by M. Virjee, Bureau for Translations, Foreign Language Division, Department of the Secretary of State of Canada

Fisheries Research Board of Canada Research Laboratory, Halifax, N.S.

1966 iegg 44 ce/ DEPARTMENIt OF THE SECRETARY OF STATE SECRÉTARIAT D'ÉTAT BUREAU FOR TRANSLATIONS BUREAU DES TRADUCTIONS FOREIGN LANGUAGES DIVISION DES LANGUES DIVISION CANADA ÉTRANGÈRES

TRANSLATED FROM TRADUCTION DE mn) - À Germa.n English

SUBJECT - SUJET Marine Research

AUTHOR - AUTEUR C.H.Brandes and R.Dietrich

TITLE IN E/yGLISH - TITRE ANGLAr Nweit-C-ee: ge-fleet-lana--en the relationship between t.w. fat and water contenta and the fat distribution in cemmem*eaa fishe e , gr ,

TITLE IN FOREIGN LANGUAGE - TITRE EN LANGUE éTRANCIèRE Betrachtungen über die Beziehungen zwischen dem Fett- und Wassergehalt und die Fettverteilung bei Konsumfischen.

REFEREpCE - RgFÉRENCE INAME OF BOOK OR PUBLICATION - NOM DU LIVRE OU PUBLICATION; Veroffentlichungen des Instituts fur Meeresforschung

PUBLISHER - éDITEUR Kommiasionsverlag Franz Leuwer

CITY - VILLE DATE PAGES Bremen (10) 1958, V010/ 299.•305

REQUEST RECEIVED KAON OUR HUMBER REQUM PAR m. Larose NOTRE DOSSIER N° (86b

DEPARTMENT TRANSLATORm Fisheries rs .M.Virjee è MINISTRE TRADUCTEUR'

YOUR NUMBER DATE COMPLETED VOTRE DOSSIER N° REMPLIE LE April 13.1966

DATE RECEIVED REÇU LE April 1966 '

WO • C

Publications of the Institute for Marine Research in Bremerhaven

1958 Volume V pages 299-305

Reflections on the relationship between the fat and water contents and the fat distribution in commercial fish

By C.-H. Brandes and R. Dietrich

Kommissionsverlag Franz Leuwer, Bremen Reflections on the relationship between the tat and water contents and the fat distributioh in commercial fish

By C.-H. Brandes and R. Dietrich

In our biological-chemical examinations carried out with

herring and redfish, we found that, regardless of the biological behaviour of the two species of fish, the ratio between water and fat in the muscles was approximately the same. This relation was expressed mathematically by the correlation coefficient and the regression coefficient, respectively, and graphically by the fat-water line (F.W.line). In that context we had already raiaed the question whether this relation might apply to all commercial fish. (Brandes-Dietrich, 1956).

To be able to answer that question, we extended our studies to six other species of fish, namely to cod (Gadus callarias), pollack (Pollachius virens), haddock (Melanogrammus aeglefinus), blue ling (Molva byrkelange), striped catfish (Anarrhichas lupus), and mottled catfish (Anarrhichas minor).

The result of our analyses showed that the fat content of lean fish very seldom was more than 1%. Since the F.W.lines for redfish and herring were based on a mean error limit of +0.65 and +0.70, respectively, that is to say, the fat content of lean fish usually falls within these limits, it is lImpossible to establish 2 a F.W.line for lean fish.

The hitherto available results of analyses of the two species of catfish indicate clearly that even in these fish with a higher fat content, a correlation between the fat and water contents must exist in the edible portions. Because of the small number of .analyses carried out so far (42), we have refrained from computing the correlation coefficient for the time being. We, however, plotted the established values for fat and water into the diagram for the F.W.lines (Fig.1), and determined the F.W.line for catfish graphically. Comparing the latter with the F.W.line for the edible portion of the herring, we see clearly that the catfish analyses are useless for computing summary correlation coefficients for fat and semi-fat fish,since the mean deviation of the two F.W.lines from each other is 3,5%.

As, therefore, our studies of lean fish and catfish did not help us in determining a common F.W.line for commercial fish, we 300 used analyses from literature of the fish species Aplodinotus grunniens Osmerus mordax, Coregonus clupeaformjs Cristivomer namaycush, and Cyprinus carpio as a supplement to our own findings. Thereby, we were able to compute the correlation coefficient from a total of 443 analyses for seven species of fish of Broup I (fat and semi- fat fish) as follows:

ç = -0.9416 F(q) = 0.0051

In Table I, we compared these summary correlation coefficients 3

with the values ifor the edible portiors of herring and redfish which we had determined separately and published already at an earlier date. We found that, in spite of the biologically very heterogeneous material, the correlation between the fat and water contents for fat and semi-fat fish was very strong and almost

complete.

10 .. Water c ntént in„y momuerwheh% 70 0 0,0 I Ebt(-1-inèe fix fete und hale», Fische Fig.l. 80 Comparison of e. b2 Fee-Li-lie nur fur Hering - e several F.W.lines - 3 FW-bilée nur für Relborech - FW-Lnie für Katfischfpmphisch ermine - ° = striped catfish 15 e = mottled catfish - 1 - F.W.line for fat and semi- 70 fat fish 2 - F.W.line for - herring only - 3 - ---, F.W.line for 65 - redfish only 4 - F.W.line for - • catfish (deter- mined graphi- 60 .. - cally) - _ Fefigeheit kr% fat content in % 55

By means cf the regression coefficient, the F.W.lines for

fat and semi-fat fish of the abOve-mentioned species were drawn, and

compared with tha P.W.lines for herring and redfish (Fig.1). The

mean deviation lies between +0.99% and -0.71% (Table 2). It is

slightly higher :han for redfish and herring. This deviation can 301

be explained frol the results of other analyses by other authors L. which we included in our computations. As we have shown, the mag- nitude of the correlation depends not only - 2,0-, the initial material,

but to a considerable extent also - On - the analytical methods used (Brandes-Dietrich 1955). Table 3 serves as an illustration of this finding.

Table 1 Relationship between fat and water contents, expressed by,the correlation coefficient Edible portion Number of analyses Standard error F (q) Herring 100 -0.9740 0.005 Redfish 267 -0.9898 0.00124 Seven different species of commercial fish, in- cluding herring and redfish 443 -0.9416 0.0051

Apart from the relation between the fat and water contents 222 in the edible portions, we were specially interested also in the regional fat distribution in the filet of the species of fish mentioned at the beginning.

As for previous studies, the fish were divided into individual parts. The location of these parts with regard to each other can for purposes of comparison, be seen in Plate 1 which alsolincludes the pictures of the divisions for herring and redfish already published (Brandes-Dietrich 1953,1956). In order to make the differences in the fat distribution in the analysed fish species particularly distinct, mean curves of the

5

Table 2

Deviations from the F.W.line for fat and semi-fat fish, edible portions Positive difference _-:IllegatileeAAifeerence 4-1 0 0ri] ;•4 Ce] 5 9 5 M .o ri .r-i •ei 0 0 0 •ri N H 0 H cd ri 0 c03 cd Cd 0 W cd cd e cd e › e › e › z › e › z0 0› Clupea harengus 73 +2.56 +0.00 +0.59 -1.73 -0.01 -0.63 (old F.W.line) Sebastes marinus 260 +2.06 +0.00 +0.65 -1.83 -0.02 -0.58 (old F.W.line)

Aplodinotus 75 +4.30 +0.11 +1.44 -1.75 -0.02 -0.63 grunniens Osmerus mordas Coregonus clupea- formis 35 +3.29 +0.01 +1.28 -1.86 -0.14 -0.98 Cristovomer namaycush Cyprinus carpio

Sum-of all species 443 +3.05 +0.03 +0.99 -1.79 -0.05 -0.71

fat content for the corresponding parts were plotted; instead of' expressing the analytical results in percentages, the water content otE.the'lhdividual parts was related to Lz fat (Fig.2). When comparing the curves plotted in this manner, we found that the fat distribution pattern in the lean fish (Group II) was almost a mirror-image of the pattern in the fat and semi-fat fish (Group I), i.e., while in Group I the fat content decreases towards the caudal fin, it A am-I 3 increases in Group II. I The (turves of mean values/computed for the 6

Table 3 Relationship between the magnitude of the correlation between fat and water contents of herring (edible por- tion) and the analytical methods used

II IV Homogenization of filet in: Mincer Mincer Mincer Multimix Methods of fat determination: Soxhlet Grossfeld Grossfeld Stoldt Determination of water content in: Drying chamber Drying chamber Drying Vacuum 96-100C,24 hrs.96-1000,50 hrs.chamber drying 96-100C, chamber, 24 hrs. 600,3 hrs Correlation coefficient -0.835 -0.927 -0 .936 -0.9 74 Standard error of F 0.023 0.012 0.005 0.005

Number of analyses 171 • 145 136 • 100 Analyses carried out by: Lucke, Lucke,h Lucke, Brandes- Brandes, Wille Bâhr Dietrich Richter, Schneider Year: 1945-1951 1931-1934 1935 1952 two groups deMonstrate this even more clearly. It is worth noting that the curves for closely related fish, both in Group I - the 304 two species of catfish - and in Group II - fish of the old genus Gadus (cod, haddock, pollack) - run almost parallel to each other. The blue ling which also belongs to the family of the Gadidae, but 7 to a different genus (Molva byrkelange), distinctly differs in the pattern of his fat distribution in the filet.

Plate 1 Location of analysed parts of several fish species with regard to each other. 1 - herring 2 - redfish

3 - blue ling

L. - catfish

5 - for cod, haddock, and pollack, one picture applicable to all three species is used

15.StraN aasiroN 50 raN "Ende" - end "Strahl" - ray 2 3 "After" - anus

3 Ends Di Pe9-d Gruppe I Gruppe,II Mean curves -ci;•cur I of fat Kopf 10 20 30 40 50 60 70 80 SO 100 110 120 130 140 190 pe , 17? content of parts. 1 t 1 It j+4 1 t 1 .....wf 1 f I I 1 I , i j /;/, i 1' Ordinate: parts

! I l- I / Abcissa: g water i related to 2 1 g fat a - herring b redfish 3 c - mottled catfish d - striped catfish e - pollack 4 f - cod ■ h - haddock - blue ling 5 W A - mean curve b c .4 d e 1 8 i for Schwan: km./ Group I B - mean curve for Group II

Looking at the curves, in particular the curve for the Gadidae, one might assume that the regional distribution of fat In the muscles of the fish is connected with the location of the centre of gravity, which is determined by habit and anatomy and undoubtedly has a certain influence on the food intake and the swimming position in the water.

There is, however, on the other hand the different behaviour of the pollack, on the one side, and of the cod and the haddock, on the other side, e.g. with regard to food intake, which depends on the different anatomy of the mouth. We know that the pollack has a protruding lower jaw without barbs, that it therefore takes in its food in an oblique direction from 1)ottom to top, and that its flight path always runs obliquely upwards. Cod and haddock, 9 on the other hand, have protruding upper jaws and tactile barbels on the lower jaw which are a clear indication for the direction of food intake being opposite to the one for the pollack. The material presently available, however, is not sufficient to allow the establishment of general relations between the regional fat distribution in the muscles and the biological behaviour of different species of fish.

Authors' address:

Dr.C.-H.Brandes, Institut fur Meeresforschung, Bremerhaven (Institute for Marine Research) Dr. R. Dietrich, Institut fur4 Meeresforschung, Bremerhaven (Institute for Marine Research)

Bibliography

BRANDES, C. H., DrisrrucH, R.: 1952. Zur Methodik der absoluten Fettbestimmung im Hering. Verôffentlichungen des Instituts für Meeresforschung in Bremer- haven, Bd. I, S. 233-235. L2, BRANDES, C. H., DIrrtucu, R.: 1952. Beitrag zur Methodik der absoluten Fett- bestimmung in Lebensmitteln, insbesondere im Hering. Deutsche Lebens- mittel-Rundschau, 48. Jahrg., S. 165-168. BRANDes, C. H., DirrRica, R.: 1953. liber die Fettverteilung im Kôrper des Herings. Verôffentlichungen des Instituts fûr Meeresforschung in Bremerhaven, Bd. II, S. 109-121. (I BRANDES, C. H., DirnucH, R.: 1953. Die Bestimmung des Fettgehaltes im abaren Anteil des Herings auf Grund der Korrelation Fett und Wasser. Vertiffent- lichungen des Instituts fût- Meeresforschung in Bremerhaven, Bd. II, S. 122-134. BRANDES, C. H., DirrtucH, R.: 1953. Zusammenfassende Betrachtungen über den Fett- und Wassergehalt im eBbaren Anteil des Herings. Fette und Seifen, Jahrg. 55, S. 533-541. (9 BRANDIS, C. H.: 1954. Liber den Fett- und Wassergehalt im Hering. Proceedings Symposium on Cured and Frozen Fish Tedmology. Sik-Publication No. 100, XII, S. 1-11.

' 7BRANDES, C. H., Dœrtucx, R.: 1956. Untersuchungen über Fett- und Wassergehalt im eBbaren Anteil des Rotbarsches (Sebastes marinus L.). Fette und Seifen, 68. Jahrg., S. 433-439. Combo:etc-1AL FISH. Aplodinotus grunniens. Vol. 13/No. 12/1951; Vol. 14/No. 10 + 11/1952; Vol. 15/No. 10+12/1953. COMMERCIAL FISH. REV.: Osmerus mordax. Vol. 14/No. 5/1952. COMMERCIAL FISH. REV.: Coregonus clupeaformis. Vol. 14/No. 4+5/1952. COMMERCIAL FISH. REv.: Cristivomer namaycush. Vol. 15/No. 2+3/1953. COMMERCIAL FISH. Rrv.: Cyprinus carpio. Vol. 14/No. 2/1953. 1 0

Translation of German titles in bibliography: 1. On the methodology of absolute fat determination in herring. 2. Contribution to the methodology of absolute fat determination in foods, in particular in herring. 3. On the fat distribution in the body of the herring.

4. Determination of fat content in the edible portion of the herring on the basis of the correlation between fat and water. 5. Surlimary of observations on the fat and water contents in the edible portion of the herring. 6. On the fat and water contents in the herring. 7. Studies on the fat and water contents in the edible portion of the redfish (Sebastes marinus L.).