Seasonal Variations of Fat and Fatty Acid Composition in Muscle Tissues of Mediterranean Octopuses

Seasonal variations of fat and fatty acid composition in muscle tissues of Mediterranean octopuses

Item Type article

Authors Ayas, Deniz

Download date 26/09/2021 04:08:33

Link to Item http://hdl.handle.net/1834/37315 Iranian Journal of Fisheries Sciences 11(4) 724-731 2012 Seasonal Variations of Fat and Fatty Acid Composition in Muscle Tissues of Mediterranean Octopuses Deniz Ayas

Received: March 2012 Accepted: June 2012

Abstract The effects of seasons on lipid and fatty acid profiles of muscle types (mantle and arm) of Mediterranean octopuses (common octopus-Octopus vulgaris and musky octopus-Eledone moschata) were investigated. The results showed that lipid levels ranged from 0.75% to 1.60% in both muscle types of octopuses which were considered as lean. Lipid levels in mantle tissues of both octopus species were higher than lipid levels in their arms. Although these two octopus species contain small amounts of lipid, they are good sources of n-3 PUFAs content (especially EPA and DHA) for all season regardless of muscle types. The highest levels of EPA were obtained from mantle and arms tissues (18.23%) of common octopus in spring. The highest levels of EPA were obtained from mantle (12.90%) and arms (12.67%) of musky octopus in autumn and winter. The levels of EPA in both of muscle tissues of common octopus were found to be higher than levels of EPA in both of muscle tissues of musky octopus. The highest DHA levels were obtained from mantle tissue (28.17%) of common octopus in summer. There were significant differences (p<0.05) in the levels of SFA, MUFA and PUFA in terms of species, season, and muscle types.

Keywords: Common octopus, Musky octopus, Season, Fatty acids, Lipid

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______Department of Seafood Processing Technology, Faculty of Fisheries, Mersin University, Mersin, Turkey. Corresponding author’s email: [email protected] 725 Ayas, Seasonal variations of fat and fatty acid composition in Octopus…

Introduction Octopuses are important species of marine Sea in February, May, August, and invertebrates consumed in the world. Total November in 2011 consist of common number of cephalopods caught were octopus (Octopus vulgaris Cuvier 1797) 4305482 and 4313510 tons were in 2007 and musky octopus (Eledone moschata and 2008, respectively (FAO, 2008). Lamarck 1798). In every season, 10 Seafood contains high level of n-3 individuals of each species were caught long chain poly unsaturated fatty acids and kept in polystyrene boxes with ice and (PUFA), especially eicosapentaenoic acid transferred to the laboratory of Faculty of (EPA, 20:5n-3) and docosahexaenoic acid Fisheries at University of Çukurova. The (DHA, 22:6n 3) (Özogul et al., 2007; sex of octopus species was identified and Ozogul et al., 2008; Nisa and Asadullah their mantle length (mm) and total weight 2011). These fatty acids are of great (g) were measured (Table 1). Meat of importance to humans for the prevention mantle and arms which is the main edible of coronary heart disease (Mozaffarian et portion of octopuses was homogenized and al., 2005; Özogul et al., 2007; Ozogul et chemical analyses were done on this part al., 2008; Ayas and Ozogul, 2011). Even of fresh samples (10 g for each though humans can synthesize EPA and replication). The analyses were performed DHA from short-chain fatty acids, this at least in triplicate. Chemical analysis synthesis is not generally sufficient Lipid analysis (Burdge and Calder, 2005; Bradbury, Lipid content was determined according to 2011). As EPA and DHA are essential the method of the Bligh and Dyer (1959) nutrients, dietary intake from seafood is method. necessary for adequate levels. However, Fatty acid analyses levels of these long chain fatty acids may Fatty acid profiles of lipid extracted from Downloaded from jifro.ir at 15:49 +0330 on Wednesday February 14th 2018 change among seafood species. Hence, the octopus samples were determined by dietary intake of EPA and DHA from gas chromatography (GC). The fatty acid seafood is dependent on the species. Also composition was analyzed by the GC fatty acids compositions of seafood may Clarus 500 with autosampler (Perkin be changed with season and muscle types. Elmer, Shelton, CT, USA) equipped with a Therefore, the aim of this study was to flame ionization detector and a fused silica investigate the effects of season and capillary SGE column (30 m 0.32 mm, ID muscle type on the lipid and fatty acid 0.25 mm, BP20 0.25 UM; SGE Analitic compositions of the common octopus and Science Pty Ltd, Victoria, Australia). The musky octopus. oven temperature was 140 oC, held for 5 min, raised to 200 oC at a rate of 4 oC/min Materials and methods and to 220 oC at a rate of 1 oC/min while Sample Preparation the injector and the detector temperature Both of octopus species were caught by were set at 220 oC and 280 oC, bottom trawling from the Mediterranean respectively. The sample size was 1 µL Iranian Journal of Fisheries Sciences, 11(4), 2012 726

and the carrier gas was controlled at 16 ps. mixture (catalog no 18919; Supelco). The split used was 1:100. Fatty acids were Triplicate GC analyses were performed identified by comparing the retention times and the results were expressed in GC area of fatty acid methyl esters with a standard % as the mean value±SD. 37-component fatty acid methyl ester

Table1: Measurements of the common octopus and musky octopus Season Species N ML (mm) weight (g) Sex

X  SX X  SX Autumn O. vulgaris 5 104.30±33.20a 370.55±125.77a ♀ O. vulgaris 5 99.65±28.64a 350.11±115.00a ♂ E. moschata 5 81.10±16.36a 100.80±57.80a ♀ E. moschata 5 80.68±14.31a 105.48±32.09a ♂ Winter O. vulgaris 5 114.11±56.45a 455.00±205.13a ♀ O. vulgaris 5 100.22±19.19a 375.49±55.33a ♂ E. moschata 5 77.89±31.01a 80.37±17.26a ♀ E. moschata 5 79.90±18.67a 95.11±10.10a ♂ Spring O. vulgaris 5 97.67±25.55a 385.57±180.77a ♀ O. vulgaris 5 119.37±44.04a 501.01±118.92a ♂ E. moschata 5 83.99±26.07a 99.27±19.11a ♀ E. moschata 5 80.07±27.44a 101.07±30.78a ♂ Summer O. vulgaris 5 115.77±40.02a 440.24±89.80a ♀ O. vulgaris 5 110.31±33.61a 444.89±101.73a ♂ E. moschata 5 90.12±22.61a 123.27±62.80a ♀ E. moschata 5 86.45±23.23a 110.22±47.90a ♂ Values in same species with different letters are significantly different

(p<0.05).ML: mantle length X  S X : SD Methyl esters were prepared by tissues and season on the lipid and fatty transmethylation using 2 M KOH in acid composition. Statistical analysis of methanol and n-heptane according to the data was carried out with the SPSS 16.0.

Downloaded from jifro.ir at 15:49 +0330 on Wednesday February 14th 2018 method described by Ichibara et al. (1996) Results with minor modification. Extracted lipids Lipid content of muscle types (10 mg) were dissolved in 2 mL n-heptane In this study, lipid levels (0.90-1.60%) in followed by 4 mL of 2 M methanolic mantle of both octopus species were KOH. The tube was then vortexed for 2 higher than lipid levels (0.75-1.07%) min at room temperature. After found in their arms (Table 2) regardless of centrifugation at 4,000 rpm for 10 min, the season. heptane layer was taken for GC analyses. Fatty acids composition Statistical analysis Saturated fatty acids (SFAs), Prior to the analyses, all data were checked monounsaturated fatty acids (MUFAs), for outliers (Z values were checked) and polyunsaturated fatty acids (PUFAs) of homogeneity of variance (Duncan test was mantle and arms of both octopus species used) was also tested. One-way ANOVA are presented in Tables 3, 4 and 5, (Analysis of Variance) was used to respectively. evaluate the effects of species, muscle 727 Ayas, Seasonal variations of fat and fatty acid composition in Octopus…

A A M M A M A M M M M A A A A M ------mantle; mantle;

OV OV EM EM EM OV OV OV EM OV EM Species/ Tissue OV EM OV EM EM

garis garis

g efg b fg k c k g cde e a cd fg a f h

Octopus vul Octopus

32.21±0.04 31.84±0.47 30.05±0.01 32.28±0.81 34.07±0.79 30.89±0.03 33.69±0.14 32.63±0.01 31.00±0.40 ΣSFA 31.61±0.19 29.80±0.04 31.09±0.11 32.90±0.14 32.25±0.55 29.69±0.08 32.09±0.04

- b b a a a

( Average±SD ) ( Average±SD

name Common Common octopusCommon Musky octopusMusky ND 0.07±0.01 0.04±0.01 ND ND ND 0.04±0.01 ND ND 0.05±0.00 C22:0 ND 0.07±0.00 ND ND ND ND

d b g b c b k d gh e k h h a h

0.02 Tissue arms arms mantle mantle

2.61±0.24 0.17±0.00 0.05±0.00 2.24±0.13 2.69±0.33 0.03±0.01 0.10±0.01 0.01±0.00 0.04±0.00 2.87±0.20 C20:0 b 1.99±0.02 2.32±0.21 2.48±0.03 ND a b 0.23± 3.13±0.16 c

e d de d e de e e e

b b c b b c a

arms

Summer 1.07±0.05 0.92±0.01 1.19±0.05 1.60±0.02 : Average±SD, ND: not detected OV detected not ND: Average±SD, :

10.78±0.32 10.10±0.13 8.85±0.22 10.30±0.26 9.06±0.09 8.46±0.06 9.66±0.05 8.85±0.01 10.04±0.05 C18:0 10.63±0.11 10.22±0.33 10.71±0.38 8.93±0.11 10.63±0.21 9.69±0.06 10.78±0.32 a b ab c

bc g c f e de b f c b c b bc d e a

11±0.01 Spring 1. 0.89±0.01 1.03±0.04 1.54±0.05 Eledone moschata Eledone

1.96±0.06 2.95±0.08 2.02±0.03 2.64±0.08 2.46±0.03 2.33±0.15 1.91±0.06 2.68±0.01 2.00±0.01 1.89±0.02 C17:0 1.72±0.04 2.05±0.04 1.92±0.00 1.97±0.12 2.26±0.06

2.50±0.08

a a a b A, -

f a b bcd c d b de b e g b fg d c h

Winter 0.90±0.12 0.75±0.01 0.93±0.02 1.15±0.06 mantle; EM mantle;

15.92±0.06 12.45±0.06 13.09±0.40 13.89±0.73 13.94±0.09 14.30±0.10 13.55±0.09 14.74±0.31 13.56±0.31 C16:0 14.98±0.03 16.83±0.09 16.30±0.06 13.41±0.05 16.15±0.27 14.30±0.19 13.94±0.09 ab a a a

b b d k c e c f c g c c d h a h

±0.01 4±0.06 es with different letters are significantly different (p<0.05). significantly letters are withdifferent es different Autumn 1.00±0.06 0.90±0.12 0.89±0.01 1.00±0.01 0.23±0.01 0.21±0.01 0.7 0.43±0.02 1.02±0.03 0.31±0.03 0.46±0.00 0.34 0.56±0.01 C15:0 0.34±0.01 0.13±0.01 0.68±0.03 0.30±0.01 0.33±0.01 0.40±0.00 0.73±0.05

Eledone moschata moschata Eledone

g e d e d de cd b bc g b f d e a h

M, M, - The effectThe of on levels lipid season of common octopus and octopusmusky (%)

: 0.72±0.02 4.28±0.03 1.84±0.09 1.45±0.08 1.81±0.06 5.97±0.59 1.50±0.25 1.79±0.16 1.25±0.20 0.91±0.04 2.45±0.16 0.86±0.09 1.10±0.13 4.01±0.18 C14:0 1.56±0.01 2.08±0.11 effects of and species season on saturated fattyacids (SFA) ofMediterranean the octopuses (%)

arms; EM arms;

Values in same lin same in Values

Table 2 bc c c b bc b a a name Latino Octopus vulgaris Eledone moschata The

ND ND 2.90±0.15 3.50±0.34 ND 3.18±0.06 2.71±0.47 1.89±0.16 C12:0 2.16±0.09 ND ND ND ND ND 2.94±0.09 2.73±0.03

Table 3

Octopus vulgaris vulgaris Octopus A, A, - Spring Summer

Winter

Season

Autumn

OV Values in same column with different letters are significantly different (p<0.05). (p<0.05). different significantly are letters with different column in same Values

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A A A A M M M M A A A A M M M M

------

A, A,

A A A A M M M M A A A A M M M M ------Species/ Tissue OV OV OV OV OV EM EM EM EM EM EM EM EM OV OV OV OV EM OV EM EM EM EM OV EM EM OV OV OV EM OV Species/ Tissue OV

g d f c c b b b bc a b e fgh k h h

m gh g l lm f k f h n

c e c d d a mantle; OV mantle;

Octopus vulgaris vulgaris Octopus ΣPUFA 52.75±0.04 52.54±0.01 52.77±0.12 50.31±0.13 52.11±0.19 47.06±0.51 47.09±0.21 46.30±0.08 46.44±0. 46.25±0.08 46.84±0.40 45.69±0.24 46.38±0.12 51.25±0.01 52.67±0.60 53.59±0.10 7.10±0.12 9.11±0.12 14.74±0.00 13.04±0.66 13.46±0.01 14.52±0.06 14.70±0.19 10.71±0.01 14.35±0.03 9.91±0.02 9.07±0.02 10.31±0.33 13.88±0.02 7.48±0.03 9.73±0.06 ΣMUFA 15.06±0.18 M, M, -

b d c b cd b b b b a a a b b d d

b c g c g f e d g fg g b g de b a

Octopus vulgaris vulgaris Octopus

n3 n9 M, - C22:6 25.39±0.08 27.65±0.50 26.86±0.11 25.04±0.57 26.50±0.55 24.99±0.42 25.49±0.28 25.31±0.02 25.09±0.29 23.95±0.26 23.97±0.23 23.90±0.33 25.12±0.01 25.17±0.23 27.29±0.81 28.17±0.40 0.08±0.01 0.10±0.00 0.44±0.00 0.11±0.00 0.48±0.02 0.31±0.01 0.26±0.01 0.21±0.01 0.42±0.02 0.34±0.06 0.42±0.05 0.08±0.00 0.44±0.04 0.24±0.02 0.08±0.00 0.06±0.00 C22:1 OV ;

c c c b c b a a d d d b f e e d c g g e fg fg h a

.03

cis t detected

D arms

ND ND 4.80±0.12 4.63±0.11 4.60±0.16 ND 2.98±0.03 2.60±0.22 ND ND 3.86±0.17 N ND ND 4.69±0.04 C20:1 4.02±0.02 0.56±0.03 0.55±0.06 C22:2 0.54±0.06 0.21±0.01 0.94±0.08 0.79±0.01 0.74±0.06 0.63±0.05 0.30±0.00 1.24±0.09 1.49±0.09 1.15±0 0.78±0.01 0.15±0.01 0.98±0.13 1.09±0.03

b ef c bc bf f f ef d de e b c d

a a

d e g c bc a b a b a bc e f h h h

Average±SD , ND: not detected, OV detected, not , ND: Average±SD n7

n3 90±0.15 98±0.10 2.31±0.02 2.80±0.12 2.49±0.01 1.95±0.08 2.39±0.13 2.94±0.09 2.97±0.05 2. 2.76±0.24 1.97±0.05 2.66±0.01 2.75±0.13 2.76±0.03 2.37±0.07 2.44±0.06 C18:1 2.61±0.23 15.56±0.15 18.23±0.07 C20:5 16.07±0.13 17.31±0.13 17.99±0.28 12.90±0.14 12.65±0.19 11.94±0.07 12.51±0.01 12.06±0.09 12.42±0.11 11.96±0.04 12.67±0.11 15. 18.23±0.32 16.44±0.18

Eledone moschata Eledone

: Average±SD , ND: no , ND: Average±SD :

b e f de f f g g de e c d e A, a ab h

- ). ).

arms e e e de c e e d e e e b d e c a

2.94±0.05 3.40±0.08 4.35±0.06 4.94±0.09 4.19±0.28 4.89±0.16 4.89±0.16 5.39±0.09 5.50±0.34 4.08±0.18 4.33±0.16 3.62±0.08 4.06±0.00 3.18±0.13 C18:1 4.42±0.04 6.06±0.09 5.34±0.16 7.90±0.15 C20:4 7.89±0.27 7.97±0.38 7.52±0.39 6.66±0.15 7.72±0.28 7.98±0.09 6.96±0.06 7.98±0.03 7.92±0.06 7.91±0.08 5.98±0.03 6.95±0.08 7.63±0.18 6.56±0.15 mantle; EM mantle;

d c c g d f f b b f e a h a h a

e c e d b e a a

Eledone moschata Eledone cis

- 0.11±0.01 0.24±0.01 0.56±0.01 0.20±0.01 0.13±0.01 0.20±0.01 0.45±0.01 0.57±0.03 0.26±0.01 0.35±0.02 0.37±0.01 0.11±0.00 0.16±0.01 0.17±0.01 C17:1 0.35±0.01 0.30±0.01 ND ND C20:2 ND ND ND 0.22±0.01 0.05±0.00 0.10±0.00 0.21±0.01 0.11±0.00 0.05±0.01 0.09±0.00 0.24±0.03 ND ND ND

cd e cd d g f b f c c c b bc a a a

Eledone moschata moschata Eledone e c b b d f de g e d g f ab h a a

e significantly different (p<0.05 different significantly e

mantle; EM mantle;

.01 M, M, n3 - 0.97±0.09 1.50±0.09 1.95±0.08 1.50±0.09 1.61±0.06 1.06±0.09 2.78±0.03 2.27±0.06 1.24±0.01 2.19±0.05 1.41±0.03 0.95±0.05 1.36±0.06 1.38±0.06 C16:1 1.24±0.02 1.29±0.08 0.33±0.01 0.13±0.01 C18:3 0.17±0 0.14±0.00 0.15±0.01 0.29±0.01 0.41±0.01 0.30±0.03 0.50±0.01 0.35±0.02 0.27±0.01 0.48±0.01 0.69±0.02 0.10±0.01 0.12±0.01 0.42±0.04

b cde d f c g e b f b ef g h a

arms; EM arms;

bc d d d d b e d e e b g f c a a 02

Eledone moschata moschata Eledone 0.05±0.00 0.09±0.01 0.09±0.00 0.15±0.01 ND 0.08±0.00 0.21±0.01 0.32±0.01 0.10±0.01 0.05±0.01 0.15±0.01 0.13±0. 0.04±0.00 0.06±0.01 C15:1 ND 0.21±0.02 M, 0.13±0.01 0.17±0.00 0.16±0.01 0.06±0.00 C18:3 0.16±0.01 0.17±0.01 0.12±0. 0.23±0.01 0.18±0.01 0.24±0.01 0.22±0.01 0.11±0.00 0.38±0.01 0.28±0.03 0.06±0.01 0.14±0.01 -

g l b k c e g l d f a a n h m

gh c k ef e g b c d fg e g k hk a a

Octopus vulgaris vulgaris Octopus

arms; EM arms; A, A, The effectsThe of and species season on polyunsaturated fatty acids (PUFA) Mediterranean the of octopuses (%) -

The effectsThe of and species season on monounsaturated fatty acids (MUFA)Mediterranean theof (%) octopuses .00±0.02 :

0.65±0.02 1 0.08±0.00 ND 0.89±0.01 0.05±0.01 0.12±0.01 0.06±0.01 0.28±0.01 1.59±0.01 0.74±0.03 0.63±0.05 0.97±0.05 1.14±0.02 C14:1 0.20±0.01 0.54±0.02 : C18:2 0.61±0.10 0.34±0.01 0.77±0.00 0.49±0.07 0.72±0.09 0.42±0.01 0.57±0.02 0.24±0.02 0.30±0.01 0.26±0.02 0.33±0.00 0.37±0.01 0.52±0.04 0.40±0.01 0.62±0.02 0.79±0.03

Table 5

mantle; OV mantle; n Table 4 Values in same column with different letters ar letters with different column in same Values Winter Summer

Spring

Autumn Season

Values in same column with different letters are significantly different (p<0.05). (p<0.05). different significantly are letters different with column in same Values Octopus vulgaris vulgaris Octopus

Seaso Autumn

Spring Winter Summer Downloaded from jifro.ir at 15:49 +0330 on Wednesday February 14th 2018 14th February Wednesday on +0330 15:49 at jifro.ir from Downloaded 729 Ayas, Seasonal variations of fat and fatty acid composition in Octopus…

Significant differences (p<0.05) in SFA autumn seasons. The major contents were observed in terms of monounsaturated fatty acids (MUFA) were species, season and muscle types (Table palmitoleic acid (C16:1, 0.95-2.78%), 3). SFA levels of mantle of common oleic acid (C18:1n-9, 2.94-6.06%), and octopus (O. vulgaris) were found to be octadecenoic acid (C18:1n-7, 1.95-2.97%) 32.25% in autumn, 34.07% in winter, in both octopus species. MUFA levels in 32.21% in spring, and 30.05% in summer both muscle tissues of common octopus whereas its levels in arms were 31.61%, were lower than MUFA levels of musky 33.69%, 32.63% and 32.90%, respectively. octopus regardless of season. The highest levels of SFA were obtained PUFA contents were significantly from mantle and arms in winter. On the different (p<0.05) in terms of species, other hand, SFA levels of mantle of musky seasons and muscle types (Table 5). PUFA octopus were 29.69%, 30.89%, 31.00% levels of mantle in common octopus (O. and 32.09% while these levels in arms vulgaris) were found to be 52.77% in were obtained as 29.80%, 31.84%, 32.28% autumn, 52.56% in winter, 51.25% in and 31.09% in autumn, winter, spring, and spring, and 53.59% in summer; however, summer, respectively. Musky octopus had PUFA levels in arms of this species were the highest SFA content in its mantle in observed as 52.11%, 52.54%, 52.75% and winter and arms in autumn. The dominat 50.31%, respectively. The highest levels of SFAs were palmitic acid (16:0), ranging PUFA were obtained from mantle from 12.45% to 16.83% and stearic acid (53.59%) and arms (52.75%) in summer (18:0), ranging from 8.46% to 10.78% in and spring. On the other hand, PUFA both species. There were significant levels in mantle of musky octopus were differences (p<0.05) in the level of MUFA 47.09%, 46.44%, 47.06% and 46.30% between species, season, and also muscle while these levels in arms were determined types (Table 4). MUFA levels of mantle of as 46.25%, 46.84%, 45.69% and 46.38% Downloaded from jifro.ir at 15:49 +0330 on Wednesday February 14th 2018 O. vulgaris were found to be 9.73% in in autumn, winter, spring and summer, autumn, 7.10% in winter, 10.71% in spring respectively. and 9.11% in summer whereas these levels Significant differences were in arms were 10.31%, 7.48%, 9.91%, observed (p<0.05) in the level of EPA and 9.07%, respectively. The highest MUFA DHA for species, season and also muscle levels of mantle and arms of common types. The highest EPA level in mantle of octopus were obtained in spring and common octopus was obtained in spring autumn seasons. MUFA levels in mantle (18.23%), followed by autumn (17.31%) of E. moschata were observed as 14.70%, although arms gave the highest content of 15.06%, 14.35% and 14.52% while these EPA in spring (18.23%). Similar to levels in arms were found to be 14.74%, common octopus, mantle of musky 13.88%, 13.04% and 13.46% in autumn, octopus had the highest EPA content winter, spring and summer, respectively. (12.90%) in autumn. However, the highest Mantle and arms of musky octopus yielded EPA content was obtained from arms of the highest MUFA contents in winter and musky octopus in winter (12.67%). Iranian Journal of Fisheries Sciences, 11(4), 2012 730

Significant differences (p<0.05) in heptadecanoic acid (C17:0), stearic acid DHA contents were observed in terms of (C18:0), palmitoleic acid (C16:1), oleic species, seasons and muscle types (Table acid (C18:1n-9), octadecenoic acid 5). DHA levels found in mantle of (C18:1n-7), arachidonic acid (C20:4 n-6), common octopus were 26.50% in autumn, cis-5,8,11,14,17-eicosapentaenoic acid 27.29% in winter, 25.17% in spring, and (EPA, C20:5 n-3) and cis-4, 7, 10, 13, 16, 28.17% in summer whereas DHA levels in 19-docosahexaenoic acid (DHA, C22:6 n- arms were 25.04%, 26.86%, 25.39% and 3). These results are in agreement with 27.65%, respectively. The highest levels of those in previous studies (Sieiro et al., DHA were obtained from mantle (28.17%) 2006; Zlatanos et al., 2006; Ozogul et al., and arms (27.65%) in summer. Regarding 2008). DHA levels in mantle of musky octopus The levels of DHA content of both (E. moschata), the results were 25.49%, octopus species were found to be similar. 25.09%, 24.99% and 25.31% whereas the Also EPA and PUFA levels in both muscle levels in arms of this species were tissues of common octopus were higher observed as 23.95%, 23.97%, 23.90% and than EPA and PUFA levels of musky 25.12% in autumn, winter, spring and octopus regardless of season. These results summer, respectively. correspond to those in previous study (Ozogul et al., 2008) Discussion The results of fatty acid Lipid content of muscle types compositions indicated that mantle and The low lipid content of octopuses (lower arms of common octopus and musky than 2%) is a feature of cephalopods octopus were very rich in n-3 fatty acids, (Table 2), reported in several studies especially EPA and DHA as reported in including Hayashi and Bower (2004), previous studies (Sieiro et al., 2006; Özyurt and et al. (2006), Sieiro et al. Zlatanos et al., 2006; Ozogul et al., 2008). Downloaded from jifro.ir at 15:49 +0330 on Wednesday February 14th 2018 (2006), Zlatanos et al. (2006), Ozogul et The amount of longer-chain n-3 al. (2008). The variations of lipid content PUFAs differs among species and can be levels in both octopus species were found influenced by a number of factors (season, to be similar. They had higher lipid sex, age). Despite the fact that both contents in spring and summer and lower octopus species contain small amounts of lipid contents in autumn and winter in both lipid, these organisms are good sources of of the muscle types, especially in mantle n-3 PUFA content (especially EPA and (Table 2). The lipid levels in mantle tissue DHA) for all seasons regardless of muscle of common octopus were reported as 1.2% types. in the study carried out by Zlatanos et al. (2006). This agrees with our observations Acknowledgements in the current study. This study was carried out with the support Fatty acids composition of University of Mersin. The major fatty acids found in both octopuses were palmitic acid (C16:0), 731 Ayas, Seasonal variations of fat and fatty acid composition in Octopus…

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