by Tadashi Ueda Original title: Gyoyu no Koseishibosan - II Maaji taiyu ni okeru hikyokusei oyobi kyokuseishishitsu no shibosan - sosei to no kankei

Transcription

1 FMB:Ma FISHERIES RESEARCH BOARD OF CANADA Translation Series No Fatty acid composition of fish oils. II. The fatty acid composition of Jack Mackerel oil, in consideration of the dependency of the polar and nonpolar lipids on the total one by Tadashi Ueda Original title: Gyoyu no Koseishibosan - II Maaji taiyu ni okeru hikyokusei oyobi kyokuseishishitsu no shibosan - sosei to no kankei From: Suisan Daigakko Kenkyu Hokoku (Journal of the Shimonoseki University of Fisheries), 20(3) : Translated by the Translation Bureau(EHH) Foreign Languages Division Department of the Secretary of State of Canada Department of the Environment Fisheries Research Board of Canada Halifax Laboratory Halifax, N. S pages typescript

2 ; '. DEPARTMENT OF THE SECRETARY OF STATE TRAI\tSLATION BUREAU MULTILINGUAL SERVICES DIVISION 03 fç CANAOA /-3 SECRÉTARIAT D'ÉTAT BUREAU DES TRADUCtIONS DIVISION DES SERVICES MULTILINGUES TRANSLATED FROM TRADUCTION DE Japanese AUTHOR AUTEUR Tadashi UEDA TITLE IN ENGLISH TITRE ANGLAIS INTO EN English FatteAcid,Composition - of F sh Oils-- II The Fatty Acid Compositions, of Jack Mackerel Oil, in Cosideration of the Dependency of the Polar and Nonpolar Lipids on the Total One. TITLE IN FOREIGN LANGUAGE (TRANSLITERATE FOREIGN CHARACTERS) TITRE EN LANGUE ÉTRANGiRE (TRANSCRIRE EN CARACTERn ROMAINS) Gyoyu no 1COseishib -o-san - II Maaji taiyu ni okeru hikyokusei oyobi kyokuseishishitsu no. shibe;san sosei to zenshib -o- san sosei to no kankei. REFERENCE IN FO.REIGN LANGUAGE (NAME OF BOOK OR PUBLICATION) IN FULL. TRANSLITERATE FOREIGN CHARACTERS, RÉFÉRENCE EN LANGUE ÉTRANGÉRE (NOM DU LIVRE OU PUBLICATION), AU COMPLET, TRANSCRIRE EN CARACTÉRES ROMAINS. ntrïnèticèan RE.."FiRENCE EN ANGLAIS Journal of The Shimonoseki University of Fisheries Vol. 20, No.3, pp ,1972 PUSLISHER- ÉDITEUR Shimonoseki University of Fisheries PLACE OF PUBLICATION LIEU DE PUBLICATION Shimonoseki, JAPAN YEAR ANNE% DATE OF PUBLICATION DATE DE PUBLICATION VOLUME ISSUE NO. HUM RO No.3 PAGE NUMBERS IN ORIGINAL NUMÉROS DES PAGES DANS L'ORIGINAL 16 NUMBER OF TYPED PAGES NOMBRE DE PAGES DACTYLOGRAPHIÉES REQUESTING DEPARTMENT MINISTÈRE-CLIENT EnvironMent.TRANSLATION BUREAU NO. NOTRE DOSSiER NO BRANCH OR DIVISION Fisheries Service TRANSLATOR (INITIA LS) EHH DIRECTION OU DIVISION TRADUCTEUR (INITIALES) PERSON REQUESTING. John Camp DEC 2 DEMANDÉ PAR!..e71. YOUR NUMBER VOTRE DOSSIER NO DATE OF REQUEST DATE DE LA DEMANDE 14,36_12 Nov. 2, 1972 SOS (RE V. 2/0.8) Fer Tei.Apue:moN i\!;.)ïl triformâ:stol \ fq it1 O enly VSE

3 I DEPARTMENT OF THE SECRETARY OF STATE TRANSLATION BUREAU fl«? SECRÉTARIAT D'ÉTAT BUREAU DES TRADUCTIONS MULTILINGUAL SERVICES DIVISION DES SERVICES DIVISION CANADA MULTILINGUES CLI ENT'S NO. DEPARTMENT DIVISION/BRANCH CITY N0 DU CLIENT MINISTÉRE DIVISION/DIRECTION VILLE Environment Fisheries Service Ottawa BUREAU NO. LANGUAGE TRANSLATOR (INITIALS) 110 DU BUREAU LANGUE TRADUCTEUR (INITIALES) Japanese EliH DEC 9 1 i972.fattyacid-compositiowoytisiloils.--ii- The Relation of the Total Lipid Fatty Acid Composition of Jack Mackerel Oil to the Fatty Acid Compositions of the Polar and Nonpolar Lipid Components by Tadashi UEDA ABSTRACT The fatty acid compositions of the lipid samples from jack mackerel (Trachurus daponicus) flesh in different seasons, before and fter th è fractionation into the polar and the nonpolar ones with silicic chroma- tography, were determined by gas-liquid chromatography. And the significances of the quadratic regression and the linear one observable in the following three relations of the factors were examined; then, the estimated linear regression equations were compared with the expectant ones. (1) The relation between the contents of the total lipid and those of either the nonpolar or the polar fraction. 0 u, SO , t The abstract is reproduced as it appears in the original paper. EH H. - F 1-; * Research Contributions of the Fisheries University, No. 662, 11. Received Jan. 24,, Cd.

4 (2) The relation between the former and the fatty acid compositions (in weight percentage) of the total lipid, or those of the nonpolar fraction, or those of the polar one. (3) The relation between the total lipid and either of the fractions in respect of the fatty acid compositions. And the results obtained were summarized as follows:. 1. The contents of the nonpolar - lipid. (y 1 ), depended closeiy on that of the total lipid (x), keeping the following re- lation; but that of the polar one (y 2 ) was independency of the latter. y 1 = x-1.02 y = 1.02 (g per 100g flesh) 2. In the nonpolar lipid, the dependency on the contents of total lipid was found in the weight percentage of the acid C and both increased in accordance with the 181 C22:6; total lipid contents. But the dependency was denied in all the other components. 3. In the polar fraction, the decreasing tendency of the weight percentage in accordance with the contents of total lipid was found in the C acid. And the increasing one was 161 found in the C acid. But the dependency on the contents 205 of total lipid was denied in all the other components. 4. In general, the fatty acid compositions of total lipid closely depended on those of nonpolar fraction, but not on those of the polar one. The influence of the fatty acid compositions of the polar lipid on those of the total lipid was not negligible in the samples of low lipid contents.

5 1. INTRODUCTION Since the introduction of gas liquid chromatography (GLC), research in the analysis of fatty acid composition of fish lipids (c.f. Ref. 1-7) has greatly increased and the accuracy of the results have also improved significantly. However, many fatty acid composition analyses deal only with test specimens obtained during a short period and examples dealing with specimens on a continuing basis over a year are very few. The fàttracid, composition of -; fish'oii varys fin species to species. (c.f. Ref. 1 & 7) but even within the same species, it can be expected that the composition may differ significantly, depending on the interrelations of the location of the catch, time of catch, stage of growth, maturity, as well as on the type of diet. Regarding the fatty acid composition of fish oil, Stansby 8) has concluded as follows: "The fattu acid composition offish oil differs from species to species, However, within the same species, even larger variations can be observed depending on individual differences of the specimen. For this reason, regarding the fatty acid composition, there is little meaning in determining the average quantities of each fatty acid but it is most important to establish the range of variation of the composition fraction*of - each fatty acid". For fish oil, it is generally recognized that there is some degree of correlation between the oil content of a fish and the fatty acid composition of the oil. Also, there have been previous reports 2) on the variations of the fatty acid composition due to the differing characteristics of the various parts of the fish body. For example, in the case of the jack mackerel, when the oil content and fatty acid composition is analyzed after the meat has been separated into the back side and the belly side, a clear difference is * The composition fraction is defined as the percent weight of a given fatty acid.

6 4 noted between the two classes 9). Also, if the fish oil is separated into polar and nonpolar lipids, a différence in the fatty acid composition between the two components is noted. The variations of fatty acid composition arising from the different causes discussed so far, may be considered as being related to the ratio of stored accumulated lipids and body structual lipids. From this point of view, using jack mackerel caught over a relatively restricted area as sampit's, muscular lipids were separated into polar and nonpolar lipids, and their - quantitative variations, and, differences in theirefatty acid" compb-, This paper reports the results of this research. sitidns were analyzed. 2. EXPERIMENTAL METHODS 2.1 TEST MATERIALS Jack mackerel of 15.5 to 27.5 cm length caught in the vicinity of Goto, Tushima Islands and offshore of Yamaguchi and Fukuoka prefectures were processed while fresh to provide.the desired test material. 2.2 EXTRACTION OF FLESH The specimen fish was first sliced into three parts along the saggital plane; the left side, right side and the bones. In order to extract the subcutaneous fat completely, the fleshy parts were removed with the skin attached and then sliced into small portions and used in the experiment. 2 3 EXTRACTION OF LIPIDS Lipids were extracted completely by the FLOCH method 10) (The extracted total lipid content will hereafter be denoted as TL. ). The solvent was dis- tilled out from the extracted solution and the remaining material approaching a steady weight value was designated as the TL mass (g/100g flesh). 2.4 SEPARATION OF POLAR AND NONPOLAR LIPIDS. The process was based on silicic column chromatography. That is, 10g of silica gel (100 mesh; produced by Mallinckrodt Co.) was activated by heating at 110 C for three hours and then mixed into 50 ml of chloroform to

7 5 produce a suspended solution. This solution was then injected into a glass tube with an inher diameter.of 20 mm to produce a chromatographic tube. One or two grams of test samples containing lipids were weighed by a high precision balance and then poured into the top of the chromatographic tube. As a first step, 200 ml of chloroform was used to dissolve out the lipids. This fractionated portionas olassified-ae the nonpolarized lipid component (hereafter denoted by NL). As a second step, 200 ml of methanol was used to dissolve out the-remaininwdipidsand. the,..fractionated portion thus.,obiaineewaeclaseitied as the polarized lipid component (hereafter denoted by PL). The fractional amounts (g/100g flesh) of NI. and PL were calculated for each classification on the basis of the mass values of the materials remaining after the solvents had been removed by distillation (rectification). In the present experiment, all solvents were redistilled and used over again. Also, the silica gel was cleansed by washing in a mixed solution of chloroform and Methanol (2:1) which was recirculated constantly. 2.5 DEGREE OF CORPULENCE t- The degree of corpulence was determined by the expression (1000 I, 3 )/W where L (cm) is the body length and W (g) is the body weight of the sample fish. 2.6 METHYL ESTERIFICATION OF THE TEST OIL SAMPLES oil samples. The boron trifluoride method was used for esterification of the 2.7 ANALYSIS OF THE FATTY ACIDS The GLC method was applied for the analysis of the fatty acids. That is, the components were identified by comparing the relative retention time of each fatty acid to that of a methyl ester standard. Also, the results of the analyses were compared to that of Ackman et al 11). The quantitative values were treated by the "full width at half peak value" method and the

8 6 resulting area lvalues were expressed in terms of weight % values. 2.8 'METHODS OF STATISTICAL ANALYSIS Since the measured values (the % composition and the lipid content g/100g flesh) follow a normal distribution (c.f. Table 1) these values were used in the calculation. In order to prove whether a relation of form y = x, or y.= k between the two s-eiected variables'existed or-not, fir -et, the second order regression equation of y with respect to x was deduced. The coeffilents.of,the,second,order. regression.equatioruwere then checked,for their, for the cases significance. Next, first order regression lines were deduced where significance did not exist, as well as for the cases where the second order regression coefficient of y was so small that the assumption of a second order effect fell within the error limits. 'For the cases where the regression coefficients were significant, it was determined further whether the first order regression coefficient could be considered as.1 and the constant term as 0 -, and. whether the entire equation could be considered as being af form y = x 12). For the cases where the first order coefficients were not significant, and for the cases where the first order coefficients were considered too small to have much influence, it was determined whether the first order coefficient was 0 and the constant equal to k, and whether the entire equation could be considered to be of form y = k was investigated. 3. RESULTS AND DISCUSSIONS 3.1 STATISTICAL DISTRIBUTIONS OF THE NET OIL CONTENT AND THE VARIOUS LIPID FATTY ACID COMPOSITION FRACTIONS When statistically processing data, large errors can be expected if the measured values do not follow a normal distribution. In such.cases a * From the context, it most likety refers to the first order regression coefficients, EH!?

9 7 "suitable variable transformation according to the type of frequency distribution must be carried out. Before proceeding with the statistical analysis, the net PL content, the composition fractions of the acids C C and 14:0' 16:1 C in PL, as well as the composition fractions of the acids C, C :1' C and in NL were taken from Tables 5 and 6 and their.frequency 201 C22 6 distributions were analyzed. 'Since the cumulative percent fractions lie approximately on a straight line when they are plotted on probability paper, they ere comparedl with normal distributions inferred froethe'linear - regression lines of the % values of the standardized variables (measured values) for the cases where the frequency of occurrence was greater than 3. Table 1 displays the results. In the 8 examples, we have r <PrtVX 2 I 0.90< < example < examples 0.75< 0.50< 0.25< ti < examples < example < example From this fact we may consider that the measured values are indeed normally distributed. Therefore, for the subsequent calculations, the % values were used directly. 3.2 THE PL AND NL CONTENTS AND THEIR RELATION TO THE TL CONTENT Table 6 shows the variation in measured values of the PL content in jack mackerel flesh over a period of one year. The relation of the. PL content to the TL content is shown in Fig. 1. The PL content values are distributed in the range of 0.53 to 1.64 (g/100g flesh) and the average value is (g/100g flesh). The second order regression coefficient (a 2) of PL content (y) with respect to the TL content (x) can be considered to be significant at the 1% level. However, the range of variation of y is

10 8 extremely small. The first order equation's regression coefficient (b 1 ) cannot be considered as significant (c.f. Table 2). When the sample linear regression equation (y = x) is compared to the expectant equation y = 1.02 (7 = 1.017), we cannot recognize a meaningful difference between the two expressions (c.f. Table 2). From the preceding facts we may consider that the PL content in jack mackerel flesh is 1.02 (g/100g flesh) independent of the TL content. The,coefficient-a 2: regardinsthenteontent:with-respeet tott. content, cannot be considered as significant, but b 1 can be regarded as significant at the 1% level (c.f. Table 2). The sample first order regression equation is y = 0.996x In the case of PL, the expectant equation was set as y = Therefore, setting the Nt expectant equation.as y = x 1.02 and comparing it to the sample firstorder regression- equation', no- Meaningfùldifference could - be noted between the two. From thia fact, it became obvious that the variation in the NI, content appears directly as a variation in the TL content (i.e. y = x ). 3.3 THE RELATION BETWEEN THE TL CONTENT AND THE FATTY ACID COMPOSITION FRACTIONS OF TL, NL AND PL The variation of the fatty acid composition of each class of lipid accompanying the variation of TL content was investigated by analysing the principle fatty acids in fish oil (C14:0, C160, C 16:1' C18:0, C 181, C182, C 20:1 C205 and C 226 ). ' THE RELATION BETWEEN THE TL CONTENT AND THE FATTY ACID COMPOSITION FRACTIONS OF THE NL CONTENT The coefficient b 1 relating the C 140 acid to the TL content can be considered as significant at the 5% level. However, because b 1 is small, B 1

11 -9 was taken as 0 and the resulting expectant equation y = 4.4 was compared to the sample regression equation. The result was that there is a difference if the coefficients only were considered, but when the equation was considered as a whole, no significant difference could be recognized. From this fact, we may consider that independent of the TL content, the C14:0 acid occupies a constant fraction in the composition of the NL. For the C and C acids, both have positive first order regresfsion- coefficienta and caube. considered assignificant-at-the -5% - ievel (c.f. Table 2). As for the other fatty acids (C160, C16:1' C 18:0' C18:2' C 20:1 and C 205 acids), they are uncorrelated to the variation in the TL content and show constant composition fractions. (c.f. The respective B o values in Table 2). However, for each fatty acid, considerable variation can be noticed in their composition fractions. For example, in the case of the acid,. its,composi:tion fraction. is,distributed between.4.7 to.8,2%. Therefore,.from the overall standpoint we should consider y = 6.4, as a suitable value. Although the composition fractions of the fatty acids in NL show constant values, composition fractions of the 'acids C1811 and C 2216 increase together with an increase in the TL content. This leads to an interesting conclusion that both acids are accumulated in the NL content. It is extremely interesting from the standpoint of conversion of fatty acids within the fish body (conversion to unsaturated compounds and elongation of the carbon chains etc.) to note that although the precursors and the fatty acids presumed to be intermediate products of the conversion process are maintained at a constant fraction, only the composition,fractions of the C 181 acid which is relatively difficult to convert into other fatty acids, and the C 226 acid which is, abundant in fish bodies and is considered as being even more difficult to

12 covert into other fatty acids, increase together with the increase in the TL content. Although this fact may be significant in terms of the C 22 6 acid content in the fish oil, definite conclusions cannot be drawn until further results are analyzed for many other fish species THE RELATION BETWEEN THE TL CONTENT AND THE FATTY ACID COi IPOSITION FRACTIONS OF THE PL CONTENT Figure 3 shows the variations of the composition fractions of the principle fatty acid in the PL content that accompany the variations of the TL content. Also, Table 2 shows the respective second order and first order sample re- gression equations. Except for the C16:I and C 205 acids, the fatty acids show constant composition fractions independent of the variations in the TL content. However, although independent of the TL content, the C 160 and C 22 6 acids show large variations. The former shows.a com Position fraction ranging from 12.3% to 33.4% while the latter shows a range of 10.3% to 42.7% and both are scattered broadly. The coefficient b 1 for both C 161 and C 205 acids wele considered as. significant at the 5% level. Comparison of the sample first order regression lines and the expectant equations y = k (The Y'value for the fractional compo- sition of each fatty acid.) for each fatty acid (c.f. Table 2), revealed no significant differences except for the C 161 and C 205 acids. For these two acids, the range of variation of the y values are small and although significant differences between the b and B values 1 1 could be recognized, when the equation is considered as a whole, y = k can be accepted as the correct representation (c.f. the Fe values). From the preceding facts we may consider that the PL fatty acid composition is approximately constant and is independent of variations in the TL content. However, for each fatty acid, a certain degree of scatter in the composition fraction is seen and this was specially large in the case of the

13 - 11- C 22:6 acid. It could be considered that the fatty acid composition for NL varys according to the changes in feed and environment but the reason for the temporal variation (independent - of the TL content) of the fatty acid composition for PL, especially the likes of C 22:6 acids, is not clear THE RELATION BETWEEN THE TL CONTENT AND THE FATTY ACID COMPOSITION OF TL Obviously, it can be considered that the fatty acid composition of TE depends - on- the fatty acid compositions,of NLand -PL. However, when. the degree of influence is considered, it is conceivable that the PL content is less important when compared to the NL content. Figure 4 displays the relation between the principle fatty acid Components of TL and the TL content. For the C acid, no significance can be recognized in both 140 a 2 and b coefficients. It can be considered that this fatty acid always maintains a constant composition fraction (y = 4.6%)., In the low TL content 1 region, the composition fraction of the acid of TL could be lower due C14.0 to the influence of the composition fraction of the C acid PL. However, no such phenomenon was observed. This result could be attributed to the smallness of the difference in the composition fractions of the C140 acid in NL and PL. The composition fraction of the C 140 acid in TL and that of NL are y = 4.6% and y = 4.4% respectively, and agree reasonably well with each other. For the C acid, the coefficient a was considered significant at the 1% level. The composition fraction of the C 160 acid in PL is y = and for NL the fraction is 7= 23.8%. Therefore, in the low oil content region the fraction is close to 19.1%. It could be considered that the fraction approaches the NL value with increasing oil content. When the ex- tremum is deduced from the sample second order regression equation, a value x (the TL content) = (g/100g flesh) is obtained. This indicates that the

14 TL content (oil content) is affected by the PL content in the region where the TL value is lower than The coefficient a 2 for the C acid was found to be not significant but 13 1 was recognized as significant at the 5% level. Since the.c acid content is y = 1.9% within PL, it does not have a great effect on the composition fraction of the C 16:I acid in TL. For TL, the content of the C 161 acid is y = 9.1% and it agrees well with that of NL (y = 9.2%). The, coefficient a 2 for. the C18:0' acid was recognized as signifi- cant at the 1% level. The C18:0 acid content of PL is % and for NL it is y = 6.4%. As a result, it can be expected that the effect of PL will appear strongly in the region where the TL content is low. That is, with an increase in the TL content, the composition fraction of the C 180 acid should change from the fraction values of PL to that of NL. The extremum deduced from the sample second order regression equation is x = (g/100g flesh). From this result, we' can see that the composition fraction of the C acid in TL approaches that of NL for the region where the TL 186 content is larger than For, the C 181 acid, the coefficient, a 2 was not recognized as significant but bl was accepted as significant at the 5% level. This acid has a composition fraction of y = 12.1 in PL and a variation of y = x in NL. Therefore, it can be considered that within TL, for low TL content, the composition fraction is affected greatly by PL and with increasing TL, it approaches the characteristics of NL. For the C 182 aci, a was recognized d 2 as significant at the 5% level but in this case the range of the y variation was small and the effect of the second order term was considered to be even smaller. Therefore, a sample linear equation (The regression coefficient could not be considered as significant.) was deduced and compared with the expectant equation (y = 1.2).

15 As a result, it became clear that y could be considered as a constant (PL y = 1.3, NL y = 1.4, TL y = 1.2). For the C 201 acid, both a 2 and b 1 could not be considered as significant. When the sample first order 'egression equation and the expectant equation y = 2.9 were compared, no significant difference could be found. From this result, we may consider that the C 201 acid occupies a constant fraction (2.97.) of the TL content. For the.020:5 acid, a 2 was considered significant at the 5% level. The extremum obtained from the sample second order regression equation gives a value of x = (g/100g flesh). From this fact, we can say that the C 205 acid content in TL is affected by the PL content in the low TL content region while in the region where TL content is higher than (10g/100g flesh), it approaches the fractional content value of the C20:5 acid in NL. For the C acid, a 2 was considered as significant at the 5% 22:6' level. Also the extremum value. is positioned towards the larger values of the TL content. Therefore, when the first order regression equation is deduced, b 1 becomes significant as well. This acid has a large difference in its composition fraction values for PL and M.' For this reason, in the region of low TL contient, the effect of the PL content appears strongly and with the increase in the TL content, the values begin to approximate the characteristics of the values for the NL content. The extremum value deduced from the sample second order regression equation gives an x value of (g/100g flesh). However, this value is larger than those values obtained from other second order regressions that were considered to be significant. Perhaps this is due to. the large value of the fractional content of C 226 acids in PL which causes the boundaries of the effects on IL content to be raised to a higher level. In general it is observed that the composition fraction of the C22:6 acid in fish oil decreases with an increase in the fish - I '

16 oil content. This Can be considered as being due to the changeover from the composition fraction in the PL content to that of the value in the NL content. The manner in which the changeover is made can be considered as being either second order in form or linear in form. 3.4 THE FATTY ACID COMPOSITION OF NL AND PL AND ITS RELATION TO THE TL FATTY ACID COMrOSITION THE FATTY ACID COMPOSITION OF NL AND ITS RELATION TO THE TL FATTY ACID COMPOSITION In order to invesigate the relation of the NL fatty acid composition to the TL fatty acid composition, the composition fraction of each fatty acid in NL and TL was compared. Figure 5 shows the relation while Table 3 displays the results of the analysis. The composition fractions of each fatty acid in NL and the corre-. can be considered to have a significant 1) 1 value between sponding values in TL, them at the 1% level except for the C14:0 acid. This fact indicates that the TL fatty acid composition relys heavily on the NL fatty acid coulposition. Also, when the sample first order regression equation and the expectant equation y = x were compared. (Table 3), the result was that no significance could be found in the difference between the two equations for the C 16:0' and C acids. In other words, as far as these acids C181, C182, C concerned, no difference could be noticed between the values of the composition fractions in TL and NL. For the composition fractions of the C 16:1' and C,,, C150 the b value for NL against TL is positive and can be : I considered as significant but it cannot be considered to be b l = I nor 1)0 = O. That is, the effects of the PL composition fractions cannot be ignored for the low TL content region..as mentioned previously, for the C 22:6 acid, in the region where

17 the TL. content is higher than (g/100g flesh), the composition fractions: of TL apprdach that of NL. Starting from this fact, We investigated the relation between NL and TL for those cases where the TL content was higher than 10 (g/100g flesh) (Since fish samples that provided TL.content.of (g/100g flesh) were few, those that.provided TL content of 10 (g/100g flesh) were itvèstigated.) and deduced a sample regression equation where b 1 could be considered as - being unity. 3,42.2.;THE',RELATIONStT4EEN.THEFATTACID, COMPOSiTiON OF PL AND TRE. FATtY ACID COMPOSITION OF TL The results of investigating th è relation between the PL and TL contents with respect to each fatty acid is shown in Table 3 and Fig.-6. The acids where b 1 could be considered as significant at the 1% or 5% level were C18:2' C and Among these fatty acids, C 20:1'.20:5 C22:6' 18:2' C20.:1 and C 205 fractions in PL and NL. acids do not show much difference in their composition significant in the relation between PL and TL. Presumably for this reason, b, 1 was considered as, For the C 226 edict, when the same investigation - was carried out for the TL contents larger than 10(g/100g flesh), b cogld no longer bé çonaidered as aigniflcant (c,f, 1 * Table 3). - - For other fatty acids, b l could not be considered as significant, but rather a result that.could be considered as y = k was obtained. From the preceding results., it became clear that the fatty acid composition of jack mackerel body oil was strongly dependent on then fatty acid composition while. the influence of the PL fatty acid composition was extremely small if it existed at all. 4. SUMMARY The body oil of jack mackerel was separated into polar and non- polar lipids and the quantity of each lipid component and its fatty acid 0 composition was investigated for a period of one year (Tables 4, 5 and 6).

18 From the results of measurements, the second order and first order regressions were investigated for, 1) the relation of nonpolar and polar lipid contents to the total lipid content, 2) the relation of the fatty acid composition of each lipid to the total lipid content, 3) the-relation of the fatty acid composition of the nonpolar and polar lipids to the total lipid fatty acid composition, and the sample first order equations were compared with the expectant equation. From the results, the following points may be inferred. 1. A relation of y = x (g/100g flesh) between the nonpolar lipid content (y) and the total lipid content (x) was obtained. A relation of y = 1.02 (g/100g flesh) between the polar lipid content (y) and the total lipid content (x) was obtained. 2. For nonpolar lipids, the composition fractions of each fatty acid can be considered to remain constant regardless - of the variations in the total lipid content (c.f. B o values in Table 2.). However, the C 181 and C22:6 acid fractions tend to increase with an increase in the total lipid content. 3. For the polar lipids, except for the and C aciàs, C16:1 205 the composition fractions of each fatty acid remain constant regardless of the variations in the total lipid content. However, the composition fraction of the acid is distributed over a wide range of values. As the-total lipid C22:6 content increases, it was noted that there is a tendency for

19 the composition fraction of the C 161 acid to decrease slightly while on thé other hand, the composition fraction of the C 225 acid has a tendency to increase. 4. While the fatty acid composition of the total lipid content depends strongly on that of the nonpolar lipid content,. there is no particular relation to the polar lipid content. However, when the total lipid content is low, the fatty acid Compositon of the polar lipid content affects that of the total lipid content. In conclusion, we wish to express our, deep gratitude to Professor Masamichi Toyomizu of Kyushu University for the many valuable instructions received during the course of this research and to Professor Hiroshi Maeda of this university who offered guidance in, and expedited much of the statistical data processing. Fronunciation uncertain..e1111

20 1) GRUGER JR.,E.H., R.W. NELSON and M.E. STANSBY, 1964: "J. Am. Oil Chem. Soc.", 41, 662 2) ARAMA, Yaichiro and Yuko TAGUCHI, 1964: "Nippon Suisan Gakkai -.Journal of Fisheries t )", 30, ) ARAMA*, Yaichir; and Y7lko TAGUCHI, 1974: "Nippon Suisan Gakkai - (Japanese JournaZ. of Fisheries t )", 3 (3, ) JANGAARD,RD.BURGHER, M.L. HUGHES - and, W.A. MAC ÇALLUM, 1963: "J. Fish. Ras. Bd. Can.", 20, 591 5) ACKMAN, R.G.and R.D. BURGHER, 1964: "ibid.", 21, 319 6) ACKMAN, R.G.and R.D. BURGHER, 1964: "ibid.", 21, 367 7) UEDA, Tadashi 1967: "Research Contributions of the Shimonoseki University of Fisheries", 16, ) STANSBY, M.E., 21967: fflpish Oils, AVI PUblishing.Co.", P. 22 shit shit (Japanese 9Y UEDA, Tadashi: TO be published 10) FOLCH, Jordi, M. LEES and G.H. SLOANE STANLEY, 1957:. "J. Biot. Chain. ", 226, ) ACKMAN, and R.D. BURGHER, 1965: "1,.T. Am. Oil Chem. Soc.", 42,38 12) KITAGAWA, Toshio and Motosaburô MASUYAMA Editors, 1952: "Shinhen T3kei Sri Hyo (New Edition: Statistical Mathematics Tables)" Published by Kawade Shobô, P * PPonunciation uncertain: ERN' 1 Uncertain due to. contraction:, EWE