Fatty acids, sterols and phospholipids levels in the

Short note

Fatty acids, sterols and phospholipids levels in the muscle of Acanthurus montoviae and Lutjanus goreensis fish E.I. Adeyeye Department of Chemistry (Analytical Unit), Ekiti State University Ado-Ekiti, Nigeria

CORRESPONDING AUTHOR: Department of Chemistry (Analytical Unit), Ekiti State University, Pmb 5363, Ado-Ekiti, Nigeria E-mail: [email protected]

The levels of fatty acids, sterols and phospholipids were determined in the muscle of Acanthurus monroviae and Lutjanus goreensis on a dry weight basis. Results showed crude fat varied from 5.15-6.25 g/100 g; SFA varied from 26.9-28.3% of total fatty acids, total unsaturated fatty acids varied from 71.7-73.2%, PUFA range was 21.2-42.2% and PUFA/SFA ranged from 0.75-1.57. Among the sterols, cholesterol was the only significant sterol with a value range of 47.479.8 mg/100 g or 100-100%. In the phospholipids, lecithin (phosphatidylcholine) was the highest in both fish samples with values of 242-305 mg/100 g. MUFA in A. monroviae was about half of the value in L. goreensis whereas the n-3 value in A. monroviae was more than double the value in L. goreensis; the n-6 values in the fish samples were almost similar. These quality parameters had these values: AA/DGLA (3.46-3.51), EPSI (0.42-1.36), EPA/DHA (0.56-1.42), LA/ALA (3.00-3.05) and MUFA/SFA (1.16-1.78). Whilst 100 g A. monroviae would provide 4.38 g fatty acids, 100 g L. goreensis would provide 3.61 g fatty acids. Key words: Lipids composition, Acanthurus monroviae, Lutjanus goreensis Acidi grassi, steroli e livelli di fosfolipidi nel muscolo del pesce Acanthurus monroviae e Lutjanus goreensis Sono stati determinati i livelli di acidi grassi, steroli e fosfolipidi, sulla sostanza secca nel muscolo di Acanthurus monroviae e Lutjanus goreensis. I risultati hanno mostrato che i grassi grezzi variavano da 5,15 a 6,25 g/100 g; gli acidi grassi saturi (SFA) variavano da 26,9 a 28,3% del totale di acidi grassi, gli acidi grassi insaturi totali variavano da 71,7 a 73,2%, il range degli acidi grassi polinsaturi (PUFA) era 21,2-42,2% e il rapporto polinsaturi/saturi variava da 0,75 a 1,57. Tra gli steroli, il colesterolo era l’unico sterolo significativo con un range di valori da 47,4 a 79,8 mg/100 g o da 100 a 100%. Nei fosfolipidi, la lecitina (fosfatidilcolina) era più alta in entrambi i campioni di pesce con valori di 242-305 mg/100 g. Gli acidi grassi monoinsaturi (MUFA) nella specie A. monroviae erano circa la metà del valore della specie L. goreensis, mentre il valore di n-3 nella specie A. monroviae era più del doppio del valore della specie L. goreensis; i valori di n-6 nei campioni di pesce erano quasi simili. Questi parametri di qualità avevano i valori di seguito indicati: Acido arachidonico (AA)/ Acido diomo-γ-linolenico (DGLA) (3,46-3,51), EPSI (0,42-1,36), Acido eicosapentaenoico (EPA)/Acido docosaesaenoico (DHA) (0,56-1,42), Acido linoleico (LA)/Acido α-linolenico (ALA) (3.00-3,05), Monoinsaturi(MUFA)/Saturi (SFA) (1,16-1,78). Mentre 100 g di A. monroviae fornirebbero 4,38 g di acidi grassi, 100 g di L. goreensis fornirebbero 3,61 g di acidi grassi. Parole chiave: composizione lipidica, Acanthurus monroviae, Lutjanus goreensis.

La rivista italiana delle sostanze grasse - VOL. XCII - APRILE/GIUGNO 2015

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INTRODUCTION

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Fish can form a very nutritious part of man’s diet; it is rich in most of the vitamins he requires, it contains a good selection of minerals, and the proteins contain all the essential amino acids in the right proportions. Although the amount of protein in fish varies a little from species to species and, on occasions, within species, the protein content for meat and for fish is roughly comparable. The processor, the nutritionist, the cook and the consumer all have a direct interest in the composition of fish. The processor needs to know the nature of the raw material before he can apply correctly the techniques of chilling, freezing, smoking or canning. The nutritionist wants to know what contribution fish can make to the diet and to health, and the cook must know for example whether a fish is normally lean or fatty in order to prepare it for the table. The consumer is interested not only in whether a particular fish tastes good, which is a matter of opinion, but also in whether it is nutritious [1]. The extreme variability of composition of different species of fish accounts to some extent for the large variety of dishes that can be made from them; unfortunately fish are all too often lumped together in one category while pork, beef, lamb and mutton are invariably regarded as being quite distinct kinds of meat. In fact there is a much greater difference in composition, flavour and texture between, say, herring, haddock, halibut and salmon than there is between butcher meats, and this range is even wider when shellfish are included [1]. Fish is known for its high nutrition due to its high protein content, phospholipids and polyunsaturated fatty acids as well as the covering percentage of the essential minerals RDA/RDI (recommended daily allowance/ intake) [2]. Polyunsaturated, especially n-3 and n-6, fatty acids are particularly important in fish, since their consumption contributes to the reduction of appearance of cardiovascular diseases [3]. Also, n-3 PUFA have been shown to be very beneficial in the prevention of inflammatory diseases [4], colon cancer [5] and disorders of the immune system [6]. Phospholipids are the main constituents of biological membranes and play an essential role in the regulation of biophysical properties, protein sorting and cell signaling pathways. They are essential components of the human diet and their absence from the human organism can lead to a number of serious diseases [7]. The two types of lagoon fish involved in this study were Acanthurus monroviae and Lutjanus goreensis. First is: Acanthurus monroviae Steindachner, 1876 has a taxonomic serial no. 172286. Taxonomic Hierarchy [8]: Kingdom: Animalia-Animal, animaux, animals Subkingdom: Bilateria Infrakingdom: Deuterostomia Phylum: Chordata – cordés, cordado, chordates

Subphylum: Vertebrata – vertebrado, vertébrés, vertebrates Infraphylum: Gnathostomata Superclass: Osteichthyes – bony fishes, poissons osseux, osteíceto, peixe ósseo Class: Actinopterygii – ray-finned fishes, spiny rayed fishes, poisson épineux, rayonnées poissons nagetires rayonnées Subclass: Neopterygii – neopterygians Infraclass: Teleostei Superorder: Acanthopterygii Order: Perciformes – perch-like fishes Suborder: Acanthuroidei – surgeonfishes Family: Acanthuridae – surgeonfishes, tangs, cirujanos, poisons-chirurgiens Genus: Acanthurus Forsskål, 1775 – lancetfishes, surgeonfishes, tangs, doctorfishes, common surgeonfishes Species: Acanthurus monroviae Steindachner, 1876-surgeonfish In Nigeria the fish is given various Nigerian local names. It is a rare fish of maximum 30 cm [9]. Second fish is: Lutjanus goreensis Valenciennes, 1830. Synonym: Lutjanus guineensis Bleeker, 1863 Family: Lutjanidae Genus: Lutjanus – red snapper Species: Lutjanus goreensis Valenciennes, 1830-red snapper FAO names: English Gorean snapper; French (Vivaneau de Gore); Spanish Pargo de Gorea. Its environments are marine; freshwater; brackish; reef-associated; depth range 0-50 m. Tropical; 34°N17°S, 27°W-14°E. Physical characteristics: max length: 80.0 cm TL male/unsexed; common length: 50.0 cm TL male/unsexed. Morphometrics: dorsal spines (total): 10; dorsal soft rays (total): 14; anal spines: 3; anal soft rays: 8. Head pointed, dorsal profile of forehead steep. Preorbital bone broad, maxilla extending to about mid-eye level. Pectoral fins of adult not reaching level of anus. Scale rows on back parallel to lateral line. Scale rows on cheek 5 or 6. Presence of narrow blue band or row of broken spots below eye. Small specimens from shallow water mainly brownish. In distribution; eastern atlantic: mainly between Senegal and the Republic of Congo; also from Cape Verde. Adults occur on rocky bottoms and in the vicinity of coral reefs. Young are frequently encountered in coastal waters, particularly estuaries and sometimes in rivers. They feed mainly on fishes and bottomdwelling invertebrates. It is commonly seen in markets, usually fresh. It is caught with hand lines, traps and gillnets [10]. The main aim of this paper was to investigate the lipids compositions (fatty acids, phospholipids and sterols) of the muscle of Acanthurus monroviae Steincdachner 1876 and Lutjanus goreensis Valenciennes


1830. There is no available information on the lipids compositions of these fishes from literature. This type of report might improve information on the food composition of lipids in the food composition Table for fishes.

MATERIALS AND METHODS Wet samples of the fishes were collected from fish trawlers from the Lagos lagoon, the samples were brought to the laboratory under ice cover. The samples were identified in the Department of Zoology of the Ekiti State University, Ado-Ekiti. The samples were opened up in the laboratory; oven-dried till constant weight; fines, bones and viscera were removed and further oven-dried at 55°C until constant weight. The cooled dried samples were ground using mortar and pestle into fine powder. Two fish samples (of each type) were used for this exercise and the ground portions were kept in plastic containers in the laboratory freezer pending analysis. About 0.25 g of each aliquot was weighed into the extraction thimble and the fat extracted with petroleum ether (40-60°C boiling range) using a Soxhlet apparatus [11]. The extraction lasted 5-6 h. The crude fat extracted was converted to the methyl ester using the boron trifluoride method [12]. The gas chromatographic conditions for the analysis of fatty acid methyl esters were as follows: - GC: HP 5890 powered with HP ChemStation rev. A09.01 [1206] software; - injection temperature: split injection; split ratio: 20:1; carrier gas: nitrogen; Inlet - temperature: 250°C; column type: HP INNOWax; column dimensions: 30 m × 0.25 mm × 0.25 µm; - oven program: initial temperature at 60°C; first ramping at 10°C/min for 20 min (260°C), maintained for 4 min; second ramping at 15°C/min for 4 min (320°C), maintained for 10 min; - detector: flame ionization detector (FID); detector temperature: 320°C; hydrogen pressure: 22 psi; compressed air: 35 psi. The peaks were identified by comparison with standard fatty acid methyl esters. The sterol analysis was as described by AOAC [13]. The aliquots of the extracted fat were added to the screw-capped test tubes. The samples were saponified at 95°C for 30 min, using 3 ml of 10% KOH in ethanol, to which 0.20 ml of benzene had been added to ensure miscibility. Deionised water (3 ml) was added and 2 ml of hexane was used in extracting the non-saponifiable materials. Three extractions, each with 2 ml of hexane, were carried out for 1 h, 30 min and 30 min respectively, to achieve complete extraction of the sterols. The hexane was concentrated to 1 ml in the vial for gas chromatography analysis and 1 µl was injected into the injection pot of GC. The gas chromatography conditions of analysis were similar to

the GC conditions for methyl esters analysis. The peaks were identified by comparison with standard sterols. Modified method of Raheja et al. [14] was employed in the analysis of the extracted oil phospholipids content determination. The gas chromatography conditions for the analysis of phospholipids were as follows: - GC: HP 5890 powered with HP ChemStation rev. A09.01 [1206] software; injection - temperature: split injection; split ratio: 20:1; carrier gas: nitrogen; inlet temperature: 250°C; - column type: HP5; column dimensions: 30 m × 0.25 mm × 0.25 µm; oven program: initial - temperature at 50°C; first ramping at 10°C/min for 20 min (250°C), maintained for 4 min; second ramping at 15°C/min for 4 min (310°C), maintained for 5 min; detector: pulse flame photometric - detector (PFPD); detector temperature: 320°C; hydrogen pressure: 20 psi; compressed air: 30 psi. For the purpose of ensuring the accuracy of the results obtained, the following things were carried out: standard chromatograms were prepared for sterols, phospholipids and fatty acids methyl esters which were then compared with respective analytical results; calibration curves were prepared for all the standard mixtures and correlation coefficient determination for each fatty acid parameter (36), same for sterols (7) and phospholipids (5). Correlation coefficient should be ≥ 0.95 for the result to be acceptable. It is a statistical index that shows the quality assurance of the calibration curve performed. It was performed with the Hewlett Packard Chemistry (HPCHEM) software. Fatty acids were listed with the chain length and double bond numbers. At the data source and reference database levels, values for individual fatty acids are usually expressed as percentages of total fatty acids since this is the most common form of analytical presentation. (It was used here). At the user data base level, values per 100 g of food are required. (Value of each fatty acid present in 100 g of fish muscle was calculated.) At all levels of data management both modes of expression are useful for comparative evaluation. A conversion factor derived from the proportion of the total lipids present as fatty acids is required [15] for converting percentages of total fatty acids to fatty acids per 100 g of food. (Crude fat level was multiplied by a conversion factor of 0.70 to convert it to total fatty acids [15]). For fatty acids expressed in g per 100 g total fatty acids, precision is best limited to the 0.1 g/100 g level, with trace being set at < 0.06 g/100 g of fatty acids [16]. Statistical analysis [17] was carried out to determine mean, standard deviation, coefficient of variation in percent. Also calculated were linear correlation coefficient (rxy), coefficient of determination (rxy2), linear regression coefficient (Rxy), and coefficient of alienation (CA) and index of forecasting efficiency (IFE). The rxy was subjected to the table (critical) value at r = 0.01 to see if significant differences existed in the values of


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fatty acids, sterols and phospholipids in the muscle of the fishes.

g/100 g) [18] and skin of barracuda having a value of 5.18 g/100 g [19]. However, the crude fat and total fatty acid values of both the skin and muscle of OreRESULTS AND DISCUSSION ochromis niloticus and Tongue sole fish were much lower than the values in the present reports: O. niloTable I depicts the crude fat and the calculated total ticus [0.23-2.25 g/100 g (crude fat); 0.16-1.57 g/100 fatty acid levels of the fish muscle on dry weight ba- g (fatty acids)] [20] and Tongue sole fish [0.03-0.36 sis. g/100 g (crude fat); 0.02-0.25 g/100 g] [21]. Both the The values between the two samples were very clo- crude fat results and the total fatty acids results were se with the coefficient of variation of 13.6 and a ratio close with each parameter having low values of coof muscle to muscle as 1.21:1.00 (total fatty acids) efficient of variation of 13.6% in each case. The low A. monroviae and L. goreensis respectively. The cru- values of the crude fat in the muscle shows that both de fat values of 5.15-6.25 g/100 g was close to the fish samples are white fish, that is fish in which the fat value 7.48 fat g/100g theacid skin of of Pellenula afzeis confined mainly to thefish liver. Table Iof- Crude and totaloffatty levels Acanthurus monroviae and Lutjanus goreensis muscle (in g/100g) liusi [18] and the value of 7.40 g/100 g in the skin Table II shows the saturated fats (SFA) and the moofParameter barracuda fish [19]; also the total calculated fatty nounsaturated A. monroviae L. goreensis Mean fats (MUFA) SDof the samples.CV % acid values range was 3.61-4.38 g/100 g which were The following members were in traces in the two samCrude fat 6.25 5.15 5.70 0.77 13.6 also close to the value in the skin of P. afezeliusi (5.23 ples: C10:0, C22:0, C24:0, C14: In-5, cis, C24:1n-15, Total fatty acids*

4.38

3.61

3.99

0.54

13.6

*Table CrudeI fat x 0.70,fat SDand = standard deviation, CV %of= Acanthurus coefficient of monroviae variation. and Lutjanus goreensis fish muscle (in g/100g) - Crude total fatty acid levels Parameter

A. monroviae

L. goreensis

Mean

SD

CV %

Crude fat

6.25

5.15

5.70

0.77

13.6

Total fatty acids*

4.38

3.61

3.99

0.54

13.6

* Crude fat x 0.70, SD = standard deviation, CV % = coefficient of variation.

Table II – Saturated and monounsaturated fatty acid composition of the muscle of A. monroviae and L. goreensis fish (% total fatty acids) Fatty acid

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A. monroviae

L. goreensis

Mean

SD

CV %

C6:0 0.00 0.00 0.00 0.00 0.00 C8:0 0.26 0.07 0.17 0.14 82.4 Table II – Saturated and monounsaturated fatty acid composition of the muscle of A. monroviae and L. goreensis fish (% total C10:0 0.05 0.02 0.04 0.03 75.0 fatty acids) C12:0 0.37 0.21 0.29 0.11 37.9 C14:0 2.61 9.01 5.81 4.52 77.9% Fatty acid A. monroviae L. goreensis Mean SD CV C16:0 13.0 16.4 14.7 2.45 16.7 C6:0 0.00 0.00 0.00 0.00 0.00 C18:0 9.17 1.21 5.19 5.63 108 C8:0 0.26 0.07 0.17 0.14 82.4 C20:0 1.43 1.36 1.39 0.05 3.60 C10:0 0.05 0.02 0.04 0.03 75.0 C22:0 0.02 0.03 0.02 0.01 33.3 C12:0 0.37 0.21 0.29 0.11 37.9 C24:0 0.00 0.00 0.00 0.00 0.00 C14:0 2.61 9.01 5.81 4.52 77.9 SFA 26.9 28.3 27.6 1.03 3.74 C16:0 13.0 16.4 14.7 2.45 16.7 C14:1n-5, cis 0.00 0.00 0.00 0.00 0.00 C18:0 9.17 1.21 5.19 5.63 108 C16:1n-7, cis 5.90 6.55 6.23 0.46 7.38 C20:0 1.43 1.36 1.39 0.05 3.60 C18:1n-6, cis 6.51 5.82 6.17 0.48 7.78 C22:0 0.02 0.03 0.02 0.01 33.3 C18:1n-9, cis 10.9 18.2 14.5 5.12 35.2 C24:0 0.00 0.00 0.00 0.00 0.00 C20:1n-11, cis 1.29 11.7 6.52 7.39 113 SFA 26.9 28.3 27.6 1.03 3.74 C22:1n-13, cis 6.44 8.16 7.30 1.22 16.7 C14:1n-5, cis 0.00 0.00 0.00 0.00 0.00 C24:1n-15, cis 0.00 0.00 0.00 0.00 0.00 C16:1n-7, cis 5.90 6.55 6.23 0.46 7.38 MUFA (cis) 31.1 50.4 40.8 13.7 33.6 C18:1n-6, cis 6.51 5.82 6.17 0.48 7.78 C18:1n-6, trans 0.01 0.01 0.01 0.00 0.00 C18:1n-9, cis 10.9 18.2 14.5 5.12 35.2 C18:1n-9, trans 0.01 0.00 0.00 0.00 0.00 C20:1n-11, cis 1.29 11.7 6.52 7.39 113 C18:1n-11, trans 0.00 0.00 0.00 0.00 0.00 C22:1n-13, cis 6.44 8.16 7.30 1.22 16.7 MUFA (trans) 0.0079 0.01 0.01 0.00 0.00 C24:1n-15, cis 0.00 0.00 0.00 0.00 0.00 MUFA (total) 31.1 50.5 40.8 13.7 33.6 MUFA (cis) 31.1 50.4 40.8 13.7 33.6 SFA = saturated = monounsaturated fatty acid C18:1n-6, trans fatty acid; MUFA 0.01 0.01 0.01 0.00 0.00 C18:1n-9, trans 0.01 0.00 0.00 0.00 0.00 C18:1n-11, trans 0.00 0.00 0.00 0.00 0.00 delle sostanze grasse0.01 - VOL. XCII - APRILE/GIUGNO MUFA (trans) La rivista italiana 0.0079 0.01 0.00 0.00 2015 MUFA (total) 31.1 50.5 40.8 13.7 33.6 SFA = saturated fatty acid; MUFA = monounsaturated fatty acid

cis, C18:1n-6, trans, C18:1n-9, trans whereas 0.00% was reported for C6:0 and C18:1n-11, trans. The CV % for the SFA and MUFA ranged from low to high values (3.63-113). The most concentrated SFA (and also fatty acid, FA) was C16:0 (13.0-16.4%) with a CV % of 16.7. Whilst C18:0 was the second most concentrated SFA in A. montoviae, C14:0 was the second most concentrated SFA in L. goreensis. The overall SFA in the two samples were close at 26.928.3 g/100 g and CV% of 3.74. Among the ten SFA parameters, 5/9 or 55.6% were more concentrated in A. monroviae than in L. goreensis whereas equivalent value of 0.00% was recorded for C6:0 in both samples. SFA with C12:0, C14:0 and C16:0 are the primary contributors to elevated blood cholesterol, and so contribute to cardiovascular disease; C14:0 being the major culprit. SFA with 12, 14 or 16 carbons generally constitute about 25%-50% of the total fat in animal foods. In the present samples all the C12:0, C14:0 and C16:0 constituted just 16.0% in A. monroviae and 25.7% in L. goreensis. C18:0 is also thought to increase the risk of cardiovascular disease. The negative effect on the heart is probably due in part to an increase in blood clotting [22]. However, C18:0 may not be as hypercholesterolemic as the other SFA (apparently because it is converted to oleic acid) [23]. The pathways of fatty acid metabolism have been reviewed by Mead and Kayama [24]. Fish are able to synthesise, de novo from acetate, and the even-chain SFA. Radio tracer studies have shown that fish can convert 16:0 to the omega-7 monoene and 18:0 to the omega-9 monoene. The 16:0 SFA is present to some degree in essentially all fats and is by far the most prevalent (usually) SFA in our diet. Considering the influence on the lipoprotein profile, 16:0 is intermediate, that is, it can be neutral when placed on a triglyceride molecule with PUFA, MUFA or 18:0, or cholesterol-raising when attached along with 12:0+14:0. In high amounts, 16:0 can even raise TC and LDL when substituted for 18:0, MUFA or PUFA in people who already have elevated TC or who eat large amounts of cholesterol. Accordingly, the general advice has been to remove as much SFA from the diet as possible [25]. Enig and Fallon [26] had enumerated many important roles in the body chemistry: - Saturated fatty acids constitute to at least 50% of the cell membranes. They are what give our cells necessary stiffness and integrity. - They play a vital role in the health of our bones. For calcium to be effectively incorporated into the skeletal structure, at least 50% of the dietary fats should be saturated. - They lower Lp (a), a substance in the blood that indicates proneness to heart disease. They protect the liver from alcohol and other toxins, such as Tylenol. - They enhance the immune system. - They are needed for the proper utilization of essen-

tial fatty acids. Elongated omega-3 fatty acids are better retained in the tissues when the diet is rich in saturated fats. - Saturated 18-carbon stearic acid and 16-carbon palmitic acid are the preferred foods for the heart, which is why the fat around the heart muscle is highly saturated. The heart draws on this reserve of fat in times of stress. - Short- and medium-chain saturated fatty acids have important antimicrobial properties. They protect us against harmful microorganisms in the digestive tract. The most concentrated monounsaturated fatty acid (MUFA) for both samples was C18:1n-9, cis with values range of 10.9-18.2% and CV% of 35.2. This was quickly followed in A. monroviae by C18:1 n-6, cis and C22:1n-11, cis in L. goreensis. The CV% in the MUFA were more varied than in SFA. The MUFA (cis, total) was lower in A. monroviae (31.1%) than in L. goreensis (50.4%) with CV% of 33.6. All the MUFA (trans, total) were in traces. Trans fats are not useful in our diet. Like saturated fats, they are relatively stable. They do not go rancid easily and hence can be used in cooking. The MUFA most commonly found in our food is oleic acid, the main component of olive oil as well as the oils from almonds, pecans, cashews, peanuts and avocados. 16-carbon palmitoleic acid has strong antimicrobial properties; it is found almost exclusively in animal fats. Oleic acid [9c-18:1 or 18:1 (n-9)] is by far the most abundant monoenoic fatty acid in plant and animal tissues, both in structural lipids and in depot fats. Olive oil contains up to 78% oleic acid, and it is believed to have especially valuable nutritional properties as part of the Mediterranean diet. It has a number of important biological properties, both in the free and esterified form. Oleic acid is the biosynthetic precursor of a family of fatty acid with the (n-9) terminal structure and with chain-lengths of 20-24 or more. Petroselinic acid (6c-18:1) occurs up to a level of 50% or more in seed oils of Umbelliferae family, including carrot, parsley and coriander. In the present report, petroselinic acid occupied the second position in A. monroviae (6.51%) and a close value of 5.82% (L. goreensis) where it is in the 5th position. Studies in vitro by Weber et al [27] revealed that triacylglycerols containing petroselinoyl [18:1(n-12)] moieties are hydrolysed by pancreatic lipase at much lower rates than other triacylglycerols. Consumption of coriander (Coriandrum sativum) oil, compared with other oils, led to significantly greater liver weights. No significant differences were observed among the groups fed with various levels of oleic acid in body weight, the weights of heart, liver, kidneys, spleen or testes, lipid content of heart, or total-cholesterol, HDL-cholesterol and triacylglycerol concentrations of blood plasma. Ingestion of coriander oil led to the incorporation of 18:1(n-12) into heart, liver and blood lipids and to a significant reduction in the concentration of arachido-


127

nic acid in the lipids of hearts, liver and blood with a concomitant increase in the concentration of linoleic acid compared with results for the other groups. The data show that petroselinic acid from dietary triacylglycerols is absorbed by rats as readily as oleic acid, but the former reduces the concentration of arachidonic acid in tissue lipids which suggests [in view of earlier studies (Mohrhauer et al [28]] petroselinic acidmediated inhibition of arachidonic acid synthesis. C16:1 is also found in rich amounts in macadamia nut, olive, canola and peanut oils. C16:1 is beneficial in reducing bad cholesterol (LDL) and it behaves like a saturated and not as an unsaturated fatty acid in its effect on HDL cholesterol [29]. It also reduces the fat deposition in blood vessels and reduces blood clot formation [30]. Gondoic acid [11-cis-eicosenoic acid (11-20:1 or 20(n-9)] is a common if minor constituent of animal tissues and fish oils, often accompanied by the 13-isomer. It is also found in rapeseed oil and seed oils of related species. Its value ranged from 1.29-11.7% and CV% of 113 in the present samples. Erucic acid (C22:1 cis-13) is a fatty acid that is appa9-18:1 11- 20:1 13-22:1 rently responsible for a favourable response of persons with nervous system [31]. The22:1 admini18:1 (n-9) 20:1 disorders (n-9) (n-9) stration of erucic acid in the diet will reduce the serum levels and brain accumulation 9-16:1 11-18:1 of a very-long-chain 13-20:1of saturated fatty acids (such as C26:0) responsible for 16:1 (n-7) 18:1 (n-7) 20:1 (n-7)

16:09-18:1 desaturation

11- 20:1 4-16:1

18:1 (n-9) Scheme 1 9-16:1 128

demyelination [32, 33]. The level of erucic acid in the present samples ranged from 6.44-8.16% with CV% of 16.7. Accumulation of certain long-chain fatty acids is associated with degenerative diseases of the central nervous system, such as behenic acid (C22:0; 0.020.03% in samples) but about 1% in beef fat [34] and lignoceric acid (C24:0; 0.00-0.00% in samples but about 1% in beef fat) as well as that of the unsaturated members of C22 and C24 group [34]. Accumulation occurs because enzymes needed to maintain turnover of those fatty acids are lacking [35]. Behenic acid has been detected to be a cholesterol-raising SFA factor in humans [36]. The production of longer-chain fatty acids of the n-9 family and n-7 family as well as the production of petroselinic acid are shown below (Scheme 1). In Table III were enumerated the various concentrations of PUFA n-6 and n-3 fatty acids. The Table contains both long-chain (LC) and very-long-chain (VLC) fatty acids (LC, 18 and VLC, 20-24) carbon atoms. The major 15-24:1 polyunsaturated fattyetcacids found in samples were linoleic acid (LA) (C18:2 cis-9, 12), arachidonic acid (AA) (C20:4 cis-5, 8, 11, 14), alpha-linole24:1 (n-9) nic acid (ALA) (C18:3 cis-9, 12, 15), eicosapentaenoic acid (EPA) 15-22:1 (C20:5 cis-5, 8, 11,etc14, 17), and docosahexaenoic acid (DHA) (C22:6 cis-4, 7, 10, 13, 16, 22:1 (n-7)

13-22:1 elongation

15-24:1 6-18:1 (petroselinic acid) etc

20:1 (n-9)

22:1 (n-9)

24:1 (n-9)

11-18:1

13-20:1

15-22:1

16:1 (n-7)

18:1 (n-7)

20:1 (n-7)

22:1 (n-7)

16:0 desaturation

4-16:1

elongation

6-18:1 (petroselinic acid)

etc

Scheme 1 Linoleic acid

Arachidonic acid

Eicosanoids (Prostaglandins,

(18:2 n-6)

(20: 4 n-6)

Thromboxanes, Leucotrienes)

Linoleic acid

Arachidonic acid

Eicosanoids (Prostaglandins,

(18:2 n-6)

(20: 4 n-6)

Thromboxanes, Leucotrienes)

Linolenic acid

Eicosapentaenoic acid (20:5 n-3)

(18:3 n-3)

Docosahexaenoic acid (22:6 n-3)

Figure 1 - Competition between n-3 and n-6 polyunsaturated fatty acids can slow down the eicosanoid formation [37] La rivista italiana delle sostanze grasse - VOL. XCII - APRILE/GIUGNO 2015

Linolenic acid

Eicosapentaenoic acid (20:5 n-3)

(18:3 n-3)

Docosahexaenoic acid (22:6 n-3)

19). LA had values of 1.31-1.41% and CV% of 5.15, AA had 2.20-2.58 and CV% of 11.3; ALA had 0.430.47% and CV% of 6.67; EPA had 8.42 -12.5% and CV% of 27.4 and DHA had 5.92 -22.3% and CV% of 82.1 with A. monroviae being consistently higher in concentration than L. goreensis in all the fatty acids mentioned above. The n-6 series are derived from LA and the n-3 series from ALA. Physiologically more important than these parent fatty acids are their elongated and desaturated derivatives of metabolities. While the desaturation steps (especially the first one) tend to be slow, the elongation steps proceed rapidly. The essential fatty acids affect the fluidity, flexibility and permeability of the membranes, they are the precursor of the eicosanoids, are necessary for maintaining the impermeability barrier of the skin and are involved in cholesterol transport and metabolism. Knowledge of the significance of the long-chain PUFA of the n-3 type, particularly EPA and DHA, for human health has increased considerably since the 1970s [38, 39]. As is well known, they are abundant in fish oils [40]; this is demonstrated particularly in A. monroviae. Many health disorders are linked with an undesired overproduction of eicosanoids [37]. These are hormone-like compounds which include prostaglandins, thromboxanes and leukotrienes. Several eicosanoids originate from AA (arachidonic acid) which can be systhesized from LA. By virtue of their competitive inhibition in the enzyme systems, fatty acids of n-3 type, especially EPA and DHA, can slow down the eicosanoid overproduction and thus prevent or cure health disorders (Fig. 1). The PUFA n-3 fatty acids have antiatherosclerotic efficacy [41]. This is mainly on: - inhibition of synthesis of vasoaggressive low density

lipoprotein (LDL); - acceleration of LDL elimination; - non-influence on the vasoprotective high density lipoproteins (HDL) or even enhanced HDL production; - decrease in the total serum triglycerides; - shifting the eicosanoid balance in favour of the antiaggregatory fraction; - reduction of the platelet aggregation and prolongation of bleeding time; - reduction of blood pressure. In many highly developed countries cardiovascular diseases pose a serious health risk and often rank first among causes of death. Thus, for many years, in Germany more than 500 per 100 000 inhabitants (1989:586) have been dying annually of heart and circulatory disorders. Compared with this, carcinoma ranks “only” second with about 260 deaths per 100 000 [42]. Death rates from ischemic heart disease (in percentage of all deaths) in the United States, Denmark and Greenland are 40.4, 34.7 and 5.3, respectively [43]. The low rate of deaths from cardiovascular disease in Greenland has been linked with the consumption of marine oils. There is evidence suggesting that long-chain n-3 polyunsaturated fatty acids also have beneficial effects on diseases other than those of the heart and of the blood vessels. They include [44]: inflammatory diseases; nephritis; strokes; arthritis; lupus erythematosis; multiple sclerosis; cancer; skin diseases; asthma. In general, lipids of marine species are characterized by low levels of linoleic acid (18:2 n-6) and linolenic acid (18:3 n-3) as well as high levels of long-chain n-3 polyunsaturated fatty acids [44]; see Table III [LA PUFA = 1.31-1.41%; ALA PUFA = 0.43-0.47%; EPA PUFA = 8.42-12.5%; DHA PUFA = 5.92-22.3%]. This

Table III - PUFA n-6 and n-3 fatty acid composition of muscle of A. monronviae and L. goreensis fish (% total fatty acids) Fatty acid C18:2n-6, cis C 18:3n-6, cis C20:2n-6, cis C20:3n-6, cis C20:4n-6, cis C22:2n-6, cis n-6 PUFA (cis) C18:2n-6 cis, trans n-6 PUFA (total) C18:3 n-3 C20:3n-3 C20:5n-3 C22:6n-3 n-3 PUFA (total)

A. monroviae 1.41 0.74 1.60 0.27 2.58 0.15 6.75 0.07 6.82 0.47 0.12 12.5 22.3 35.3

L. goreensis 1.31 0.63 1.73 0.26 2.20 0.21 6.34 0.08 6.41 0.43 0.02 8.42 5.92 14.8

Mean 1.36 0.69 1.67 0.27 2.39 0.18 6.55 0.08 6.62 0.45 0.07 10.4 14.1 25.1

SD

CV %

0.07 0.07 0.09 0.01 0.27 0.04 0.29 0.01 0.29 0.03 0.07 2.86 11.6 14.5

5.15 10.1 5.39 3.70 11.3 22.2 4.43 12.5 4.38 6.67 100 27.4 82.1 58.0

PUFA = polyunsaturated fatty acid (essential fatty acid).


129

130

trend was also observed in various fatty acid compo- high concentrations (1.8 g per day for four weeks) of sition (%) of several marine fish lipids [44]. Eicosap- eicosapentaenoic acid ethyl ester made from sardine entaenoic acid (20:5 n-3, EPA) and docosahexaenoic oil were able to suppress platelet aggregation [52]. acid (22:6 n-3, DHA) are the predominant n-3 fatty Further extensive research on the beneficial effect of acids [45]. Because of the low content of n-6 fatty n-3 fatty acids from fish oils on the prevention of athacids in marine fish, the ratio of total n-3 to n-6 fatty erosclerosis was carried out in the United States as acids (essential fatty acid ratio) is high, varying be- well as in many other countries, e.g. in Canada [53], tween about 5 and more than 10 [44]. the UK [54], Germany [55] and in Australia [56]. The typical fatty acid composition of marine fish oils Table IV contains the statistical analysis result from results from the fatty acid composition of the marine Tables II and III data. The correlation coefficient (rxy) phytoplankton. These fatty acids reach the fish via the was high and significantly different in the two samples. food web [46]. The coefficient of regression (Rxy) showed that for evThere is a huge variation in fatty acid composition of ery one unit increase in the fatty acids of A. monrodifferent fish n-3 of fatty the acid same species,ofmainly viae, there was a goreensis corresponding increase of 1.3618 Table III -individual PUFA n-6 and composition muscle of A. monronviae and L. fish (% total fatty acids) owing to differences relative to food as was shown for in L. goreensis. Both the general mean was close in Fatty acid herring and mullet A. monroviae L. goreensis Mean SDsimilar observations CV % menhaden, oil [47]. This condition both samples (3.4483-3.4521%); may also result in the different species within similar were noted for standard deviation (SD) having a range C18:2n-6, cis 1.41 1.36 0.07 5.15 environment as seen in the present samples (Table 1.31of 5.1307-5.4087 and coefficient of variation (149C 18:3n-6, cis 0.74 0.63 0.69 0.07 10.1 III). 157%) showing that the fatty acids compositions were C20:2n-6, 1.60 1.67 in the samples. 0.09 The coefficient 5.39 Marine fishcisdepend on a dietary supply of polyunsatu- 1.73variously scattered of C20:3n-6, cis 0.27 0.26 0.27 0.01 3.70 rated n-3 acids for rapid growth, since in many cases alienation (CA) was high at 0.7707 leading to low level C20:4n-6, 2.58 2.39 0.27 (IFE) (0.2293). 11.3 This they have cis only a very limited desaturase activity [48]. 2.20of index of forecasting efficiency C22:2n-6, cistwo early long-term studies 0.15 0.18 0.04 22.2 levels There were of the benefi- 0.21means the relationship between the fatty acids cial of eating fish with regard n-6effect PUFA (cis) 6.75 to the incidence 6.34between the two 6.55samples would 0.29be difficult to 4.43predict ofC18:2n-6 heart attacks out over a pe- 0.08because the error 77.0 7% cis, trans [38]. One was carried 0.07 0.08 of prediction 0.01is high at 12.5 riod 19 (total) years in Seattle (Washington) [49], the other 6.41since IFE represents a reduction n-6 of PUFA 6.82 6.62 0.29of error of prediction 4.38 over period of 20 years in Zutphen (The Nether- 0.43of relationship 0.45 which is just 22.93%. C18:3a n-3 0.47 0.03 6.67 lands) [50]. Both projects clearly showed that conSome quality parameters of the fatty acids of A. monC20:3n-3 0.12 0.02 0.07 0.07 100 sumption of fish can reduce the risk of ischemic heart roviae and L. goreensis muscle as compiled from C20:5n-3 12.5 8.42 10.4 2.86 27.4 diseases. Tables II and III are shown in Table V. Parameters that C22:6n-3 22.3 5.92 14.1 11.6 82.1 Danish research on Eskimo food in Greenland sug- were highly comparable in the fish samples were: SFA n-3 PUFA (total) 35.3 14.8 25.1 14.5 58.0 gests that there must be a connection between the [26.9-28.3%; CV% of 3.74]; CLA [0.07-0.078%; CV% PUFAamounts = polyunsaturated acid (essential fatty acid). large of fishfatty eaten there and the low inci- of 12.5]; n-6 PUFA (total) [6.41-6.82%; CV% of 4.38]; dence of heart attacks among the inhabitants [52]. total UFA (MUFA + PUFA) [71.7-73.2%; CV% of 1.53] This was confirmed by exhaustive investigations and those with high differences were: total cis-MUFA in Japan. In consequence of the high intake of fish [31.1-50.4; CV% of 33.6]; total trans- MUFA [0.01in families of fishermen living along the coast, their 0.01%; CV% of 0.00]; n-3 PUFA [14.8 -35.3%; CV% mortality rate owing to ischemic heart disease and of 58.0]; total MUFA [31.1-50.5%; CV% of 33.6] and cerebrovascular diseases is manifestly lower than in total PUFA [21.2-42.2%; CV% of 46.8]. The relative farmer families [51]. Both EPA and DHA have an an- amounts of PUFA and SFA in dietary oils is important tithrombotic effect, and it was in a clinical test that in nutrition and health. The ratio of PUFA/SFA (P/S ratio) is therefore important in determining the detriTable IV - Statistical analysis of the results from Tables II and mental effects of dietary fats. The higher the P/S ratio the more nutritionally useful is the oil. This is because Table III the severity of atherosclerosis is closely associated with the proportion of the total energy supplied by Statistics A. monroviae L. goreensis SFA and PUFA fats [57]. The present P/S varied berxy 0.6372 tween 0.75-1.57 which were averagely normal but 2 0.4060 rxy much better in A. monroviae than L. goreensis. The Rxy 1.3618 n-6 and n-3 FAs have critical roles in the membrane Mean 3.4521 3.4483 structure [58] and as precursors of eicosanoids (Fig. SD 5.4087 5.1307 1), which are potent and highly reactive compounds. CV % 157 149 Since they compete for the same enzymes and have CA 0.7707 different biological roles, the balance between n-6 IFE 0.2293 and n-3 FAs in the diet can be of considerable imporRemark * tance [59]. The ratio of n-6 to n-3 or specifically LA to ALA in the diet should be between 5:1 and 10:1 rxy = correlation coefficient; Rxy = regression coefficient; CA = coefficient of alienation; IFE = index of forecasting efficiency; * = [59] or 4-10 g of n-6 FAs to 1.0 g of n-3 FAs [60]. As LA is almost always present in foods, it tends to results significantly different at n-2 and r = 0.01


Table V - Some quality parameters of the fatty acids of A. monroviae and L. goreensis muscle extracted from Tables II and III Parameter Total SFA Total cis-MUFA Total trans-MUFA CLA (18:2n trans-9, cis-11) n-6 PUFA (total) n-3 PUFA (total) Total MUFA Total PUFA Total UFA =(MUFA+PUFA) Total Fatty Acid AA/DGLA EPSI EPA/DHA LA/ALA PUFA/SFA MUFA/SFA n-6/n-3

A. monroviae 26.9 31.1 0.01 0.07 6.82 35.3 31.1 42.2 73.2 100 3.51 1.36 0.56 3.00 1.57 1.16 0.19

L. goreensis 28.3 50.4 0.01 0.08 6.41 14.8 50.5 21.2 71.7 100 3.46 0.42 1.42 3.05 0.75 1.78 0.43

Mean 27.6 40.8 0.01 0.08 6.62 25.1 40.8 31.7 72.4 100 3.49 0.89 0.99 3.03 1.16 1.47 0.31

SD

CV %

1.03 13.7 0.00 0.01 0.28 14.5 13.7 14.8 1.11 0.04 0.66 0.61 0.04 0.58 0.44 0.17

3.74 33.6 0.00 12.5 4.38 58.0 33.6 46.8 1.53 1.15 74.2 61.6 1.32 50.0 29.9 54.8

UFA = unsaturated fatty acid; EPSI = essential PUFA status index

be relatively more abundant in animal tissues. This is supported in the present report as follows: C18:2 (n6) ranged between 1.31-1.41% whereas C18:3 (n-3) ranged from 0.43-0.47%. In turn, these FAs are the biosynthetic precursors in animal systems of C20 and C22 PUFAs, with 3-6 double bonds, via sequential desaturation and chain-elongation steps (desaturases in animal tissues can only insert a double bond) [61]. Looking at n-6/n-3 in Table V as well as LA/ ALA, none of the samples fell within the expected ratio, we had 0.191-0.429 in n-6/n-3 and 2.998-3.050 in LA/ALA; i.e. 0.19:1.00-0.43:1.00 in n-6/n-3 and 3.00:1.00-3.05:1.00 in LA/ALA. Both LA and ALA (and invariably n-6/n-3) need adjustments from other food sources. The relative proportion of MUFA/SFA is an important aspect of phospholipid compostions and changes to this ratio have been claimed to have effects on such disease states as cardiovascular disease, obesity, diabetes, neuropathological conditions and cancer. For example, they have been shown to have cyto-protective actions in pancreatic β-cells. cis-Monoenoic acids have desirable physical properties for membrane lipids in that they are liquid at body temperature, yet are relatively resistant to oxidation. They are now recognized by nutritionists as being beneficial in the human diet. Present results gave values of MUFA/SFA as 1.16-1.78 (Tab. V) which are good enough. A high ratio between AA and GLA, as an indicator of Δ-5 desaturase activity, in the skeletal muscle phospholipids has been related to good insulin activity [62]; the AA/DGLA in the samples ranged as 3.46-3.51 (Tab. V) which were good results. For the assessment of the essential PUFA status of an individual, the total

amount of the various EFA and PUFA in plasma or erythrocyte phospholipids is a useful indicator [63]. The following are further used as additional status markers to reliably assess the functional PUFA status [62]. The best known marker is mead acid [trivial name for all-cis-icosa-5, 8, 11-trienoic acid (20:3n9)]. The synthesis of this fatty acid is promoted if there are insufficient concentrations of LA and ALA to meet the need for the synthesis of long-chain PUFA. EPA and DHA inhibit mead acid synthesis; the presence of mead acid indicates a general shortage of all essential PUFA. The present results had ratios of EPA/ DHA as 0.56-1.42 and no mead acid was produced. Another suitable indicator of essential PUFA status is the essential PUFA status index (EPSI), which is the ratio between all essential PUFA (the sum of all n-3 and n-6 FAs) and all non-essential unsaturated FAs (the sum of all n-7 and n-9 FAs). The higher the EPSI status indexes the better the essential PUFA status. The present results had values of EPSI range of 0.42-1.36 which were between < average (40%) to > average (135%). Finally, if there is a functional shortage of DHA, the body starts to synthesise the most comparable long-chain PUFA of the n-6 family, osbond acid (C22:5 n-6). Therefore, under steady state conditions, the ratio between DHA and osbond acid is a reliable indicator of the functional DHA status [64]. Therefore the PUFA in the fish samples could not cause functional distress. Table VI contains the fatty acids distribution per 100 g sample as food. The values produced from SFA, n-6 PUFA and n-3 PUFA were consistently higher in the A. monroviae than L. goreensis but vice versa in MUFA. Further on A. monroviae, its AA > LA in the


131

Table VI - Values of fatty acids per 100 g muscle of A. monroviae and L. goreensis as food Values in 100 g sample Fatty acid

132

A. monroviae

C6:0 C8:0 C10:0 C12:0 C14:0 C16:0 C18:0 C20:0 C22:0 C24:0 SFA C14:1n-5, cis C16:1n-7, cis C18:1n-6, cis C18:1n-9,cis C20: 1n-11, cis C22:1n-13, cis C24:1n-15, cis MUFA (cis) C18:1n-6, trans C18:1n-9,trans C18: 1n-11, trans MUFA (trans) MUFA (total) C18:2n-6, cis C18:3n-6, cis C20:2n-6, cis C20:3n-6, cis C20:4n-6, cis C22:2n-6, cis n-6 PUFA (cis) C18:2n-6 cis, trans n-6 PUFA (total) C18:3n-3 C20:3n-3 C20:5n-3 C22:6n-3 n-3 PUFA (total) Total

0.01 0.00 0.02 0.11 0.57 0.40 0.06 0.00 0.00 1.18 0.00 0.26 0.29 0.48 0.06 0.28 0.00 1.36 0.00 0.00 0.00 1.36 0.06 0.03 0.07 0.01 0.11 0.01 0.30 0.00 0.30 0.02 0.01 0.55 0.98 1.54 4.38

L. goreensis 0.00 0.00 0.01 0.33 0.59 0.04 0.05 0.00 0.00 1.02 0.00 0.24 0.21 0.66 0.42 0.29 0.00 1.82 0.00 0.00 0.00 1.82 0.05 0.02 0.06 0.01 0.08 0.01 0.23 0.00 0.23 0.02 0.00 0.30 0.21 0.53 3.61

n-6 group; in n-3 values DHA > EPA. The calculation accounted for all the total fatty acids as calculated by crude fat × conversion factor for the samples. The National Institute of Health has published recommended daily intakes of FAs; specific recommendations included 650 mg of EPA and DHA, 2.22 g/day of ALA and 4.44 g/day of LA. However, the Institute of Medicine has recommended DRI (dietary reference intake) for LA at 12 to 17 and ALA at 1.1 to 1.6 g for adult women and men, respectively. Although seafood is the major dietary source of n-3 FAs, a recent

Mean

SD

CV %

0.00 0.00 0.02 0.22 0.58` 0.22 0.06 0.00 0.00 1.10 0.00 0.25 0.25 0.57 0.24 0.29 0.00 1.59 0.00 0.00 0.00 1.59 0.06 0.03 0.07 0.01 0.10 0.01 0.27 0.00 0.27 0.02 0.00 0.43 0.60 1.04 4.00

0.00 0.00 0.01 0.16 0.01 0.25 0.01 0.00 0.00 0.11 0.00 0.01 0.06 0.13 0.25 0.01 0.00 0.33 0.00 0.00 0.00 0.33 0.01 0.01 0.01 0.00 0.02 0.00 0.05 0.00 0.05 0.00 0.00 0.18 0.54 0.71 0.54

0.00 0.00 50.0 72.7 1.74 114 16.7 0.00 0.00 10.0 0.00 4.00 24.0 22.8 104 3.45 0.00 20.8 0.00 0.00 0.00 20.8 16.7 33.3 14.3 0.00 20.0 0.00 18.5 0.00 18.5 0.00 0.00 41.9 90.0 68.3 13.5

fatty acid intake survey indicated that red meat also serves as a significant source of n-3 fatty acids for some population [65]. The PUFA content of some selected foods for LA are (mg/100g): beef (muscle only), 80; calf’s kidney, 61; chicken (breast), 980; chicken (leg), 370; horse meat (average), 160; pork (muscle only), 110; turkey (breast), 180; turkey (leg), 750; veal (muscles only), 197. For ALA (mg/100g): calf’s kidney, 61; chicken (breast), 2.7; chicken (leg), 10; horse meat (average), 260; pork (muscle only), 25 and veal (muscle only),


9.1 [66]. The present level of LA and ALA are in good relationship with the literature values having values of 47.7-61.6 mg/100g (linoleic acid) and 15.5-20.6 mg/100g (alpha linolenic acid). The statistical analysis of the data in Table VI is shown in Table VII. Most of the values (rxy, rxy2, CV%, CA and IFE) in Table VII were similar to the values in Table IV. (This is generally appropriate since results that gave birth to Table IV also gave birth to the values in Table VI where Table VII was generated). However, while Rxy in Table IV was 1.3618, it was 0.0491 in Table VII; also while SD was 5.1307-5.4087 in Table IV it was 0.1243-0.1510 in Table VII. As in Table IV, high significant difference also occurred in Table VII. The energy in food is held in the form of fat, carbohydrate, protein and alcohol. Each gram of fat contains approximately 9 kilocalories (37 kJ) [67]. This value was used to calculate the energy levels of the various samples. The energy density in the samples due to fat ranged from 133-162 kJ/100 g (about 32.49-39.42 kcal/100 g) (Tab. VIII). The 1990 Canadian RNI (Recommended Nutrient Intakes) included specific amounts for 3n-3 fatty acids and 2n-6 fatty acids. For n-3 FAs, the RNI is 0.5% of total energy or 0.55 g/1000 kcal [68]. For energy contribution in the samples, the following was observed: A. monroviae [n-3 PUFA (total)] > MUFA (total) > SFA > n-6 PUFA (total), L. goreensis [MUFA (total) SFA > n-3 PUFA (total) > n-6 PUFA (total)]. In these samples, the n-3 FAs contributed 14.8-35.3% of total energy, whereas n-6 FAs contributed 6.41-6.82% of total energy and SFA contributed 26.9-28.3% of total energy. Remember, total energy contribution by the samples ranged from 133-162 kJ/100 g (about 32.49-39.42 kcal/100 g). For optimum weight loss, reduce your overall fat/oil consumption to a sensible level. A level of 15-20% of your total calories should come from fat- and the majority of that should be essential fatty acids. To determine how many grams of fats this translates into, you multiply your total daily calories by 15% (20% for the high end of the range) and then divide by 9, which is the number of calories in a gram of fat. Here is an example: 2500 daily calories × 0.15 = 375/9 = 41.7 or 42 g of total fat per day-the bulk of which should be EFAs. It is known that 20% energy from fat is consistent with good health. With 41.7 g of total fat per day, the samples with values of 3.61-4.38 g/100g fatty acids would only be able to be minor sources of energy to its consumers. In Table IX, we have the sterol levels of the muscle of A. montoviae and L. goreensis. The total level of cholesterol ranged from 47.4-79.8 mg/100g or ratio 1.00:1.68. Of these total level of the sterols, cholesterol occupied a level of 100-100% meaning that cholesterol was the main sterol of the samples. Cholesterol is a high-molecular weight alcohol that is manufactured in the liver and in most human cells. Like SFA, the cholesterol we make and consume plays many vital roles.

Table VII - Statistical analysis of the results from Table VI Statistics rxy rxy2 Rxy Mean SD CV % CA IFE Remark

A. monroviae

L. goreensis 0.6372 0.4060 0.0491

0.1510 0.2366 157

0.1243 0.1850 149 0.7707 0.2293 *

* = results significantly different at n-2 and r = 0.01

Along with SFA, cholesterol in the membrane gives our cells necessary stiffness and stability. When the diet contains an excess of PUFA, these replace SFA in the cell membrane, so that the cell wall actually becomes flabby. When this happens, cholesterol from the blood is “driven” into the tissues to give them structural integrity. This is why serum cholesterol levels may go down temporarily when we replace SFA with PUFA oils in the diet [69]. Cholesterol acts as a precursor to vital corticosteroids, hormones that help us deal with stress and protect the body against heart disease and cancer; and to the sex hormones like androgen, precursor to vitamin D, a very important fat-soluble vitamin needed for healthy bones and nervous system, proper growth, mineral metabolism, muscle tone, insulin production, reproduction and immune system function. The bile salts are made from cholesterol. Bile is vital for digestion and assimilation of fats in the diet. Recent research shows that cholesterol acts as an antioxidant [70]. This is the likely explanation for the fact that cholesterol levels go up with age. As an antioxidant, cholesterol protects us against free radial damage that leads to heart disease and cancer. Cholesterol is needed for proper function of serotonin receptors in the brain [71]. Low cholesterol levels have been linked to aggressive and violent behaviour, depression and suicidal tendencies. Mother’s milk is especially rich in cholesterol and contains a special enzyme that helps the baby utilize this nutrient. Babies and children need cholesterol –rich foods throughout their growing years to ensure proper development of the brain and nervous system. Dietary cholesterol plays an important role in maintaining the health of the intestinal wall [72]. This is why low-cholesterol vegetarian diets can lead to leaky gut syndrome and other intestinal disorders. However, like fats, cholesterol may be damaged by exposure to heat and oxygen. This damaged or oxidized cholesterol seems to promote both injury to the arterial cells as well as a pathological buildup of plaque in the arteries [73]. The statistical analysis of the variances from Table IX is shown in Table X. Both rxy and rxy2 stood at 1.00 each.


133

Table VIII - Energy values of fatty acids per 100 g muscle of A. monroviae and L. goreensis as food Values in kJ/100 g sample

134

Fatty acid

A. monroviae

L. goreensis

Mean

SD

CV %

C6:0 C8:0 C10:0 C12:0 C14:0 C16:0 C18:0 C20:0 C22:0 C24:0 SFA C14:1n-5, cis C16:1n-7, cis C18:1n-6, cis C18:1n-9, cis C20:1n-11, cis C22:1n-13, cis C24:1n-15,cis MUFA (cis) C18:1n-6, trans C18:1n-9, trans C18:1n-11, trans MUFA (trans) MUFA (total) C18:2n-6, cis C18:3n-6, cis C20:2n-6,cis C20:3n-6, cis C20:4n-6, cis C22:2n-6, cis n-6 PUFA (cis) C18:2n-6, cis, trans n-6 PUFA (total) C18:3n-3 C20:3n-3 C20:5n-3 C22:6n-3 n-3 PUFA (total) Total

0.43 (0.26%) 0.09(0.05%) 0.60 (0.37%) 4.23 (2.61%) 20.1 (13.0%) 14.8 (9.17%) 2.31 (1.43%) 0.03 (0.02%) 0.00 (0.00%) 43.5(26.9%) 0.00 (0.00%) 9.55 (5.90%) 10.5 (6.51%) 17.7(10.9%) 2.09 (1.29%) 10.4 (6.44%) 0.00 (0.00%) 50.3 (31.1%) 0.01 (0.01%) 0.00 (0.00%) 0.01 (0.01%) 50.3 (31.1%) 2.28 (1.41%) 1.19 (0.74%) 2.58 (1.55%) 0.44 (0.27%) 4.18 (2.58%) 0.24 (0.15%) 10.9 (6.75%) 0.11 (0.07%) 11.0 (6.82%) 0.76 (0.47%) 0.20 (0.12%) 20.2 (12.5%) 36.1 (22.3%) 57.2 (35.3%) 162

0.09 (0.07%) 0.02 (0.02%) 0.28 (0.21%) 12.0 (9.01%) 21.9 (16.4%) 1.61 (1.21%) 1.81 (1.36%) 0.04 (0.03%) 0.01 (0.00%) 37.8(28.3%) 0.01 (0.00%) 8.74 (6.55%) 7.77 (5.82%) 24.2 (18.2%) 15.6 (11.7%) 10.9 (8.16%) 0.01 (0.00%) 67.3 (50.4%) 0.02 (0.00%) 0.00 (0.00%) 0.02 (0.01%) 67.3 (50.5%) 1.75 (1.31%) 0.85(0.63%) 2.31 (1.73%) 0.35 (0.26%) 2.93 (2.19%) 0.28 (0.21%) 8.45 (6.34%) 0.10 (0.08%) 8.55 (6.41%) 0.58 (0.43%) 0.03 (0.02%) 11.2 (8.42%) 7.89 (5.92%) 19.7 (14.8%) 133

0.26 0.06 0.44 8.12 21.5 8.23 2.06 0.04 0.00 40.7 0.00 9.14 9.14 21.0 8.88 10.7 0.00 58.8 0.02 0.00 0.02 58.8 2.02 1.02 2.45 0.40 3.56 0.26 9.68 0.11 9.78 0.67 0.12 15.7 22.0 38.4 148

0.24 0.05 0.23 5.49 0.64 9.35 0.35 0.01 0.00 4.03 0.00 0.57 1.93 4.63 9.59 0.35 0.00 12.0 0.01 0.00 0.01 12.0 0.37 0.24 0.19 0.06 0.88 0.03 1.75 0.01 1.76 0.13 0.12 6.36 19.9 26.5 20.5

92.5 82.5 51.4 67.7 2.96 114 17.0 25.0 0.00 9.90 0.00 6.24 21.1 22.1 108 3.27 0.00 20.4 50 0.00 50.0 20.4 18.3 23.5 7.76 15.0 24.7 11.5 18.1 9.09 18.0 19.4 100 40.5 90.6 68.9 13.9

The Rxy was very low at -0.00038, hence the value of rxy as 1.00. The mean and SD of A. monroviae each almost doubles its corresponding value in L. goreensis although the CV% was similar (265) in both samples. The CA was 0.00 and hence no value was calculated for IFE. However, significant difference occurred in the sterol composition of the two samples. Table XI shows the levels of the various phospholipids. The concentration level of the phospholipids was close at 443-533 mg/100g with CV% of 13.2 and a ratio concentration of A. monroviae: L. goreensis as 1.00:1.21. Phosphatidylcholine (PC or lecithin)

was the most concentrated phospholipid in the two samples forming levels of (mg/100g): 242 (or 54.8%) in A. monroviae and 305 (or 57.2%) in L. goreensis. The PC is the building block of membrane bilayers, it is also the principal phospholipid circulating in plasma, where it is an integral component of the lipoproteins, especially the HDL [68]. Phosphatidylethanolamine/cephalin (PE) was in the second position in concentration in the two fish samples with a value of 131 mg/100g (29.7%) (A. monroviae) and 54.9 mg/100g (29.0%) (L. goreensis). PE is found in all living cells, although in human physiology it is found


Table IX - Sterol levels (mg/100 g) of the muscle of A. monroviae and L. goreensis Sterol

A. monroviae

L. goreensis

Mean

SD

CV %

Cholesterol

47.4 (100%)

79.8 (100%)

63.6

Ergosterol Sterol Campesterol Cholesterol Stig-masterol Cholestanol 5-Avenasterol Ergosterol Sitosterol Total Campesterol

7.24 e-4 A. monroviae 9.40 e-4 47.4 5.31 (100%) e-5 6.13 4.41 e-4 7.24 8.33 e-4 e-5 47.4 e-4 9.40 5.31 e-5 4.41 e-4 8.33 e-5 47.4

22.9 0.97 1.13 SD 0.08 22.9 1.11 0.97 0.02 1.13 0.27 22.9 0.08 1.11 0.02 0.27 22.9

36.0 17.9 17.5 CV % 0.87 36.0 24.5 17.9 0.36 17.5 3.30 36.0 0.87

Table IX - Sterol levels g) of the muscle of4.75 A. monroviae and L. goreensis Cholestanol 6.13(mg/100 e-4 e-4 5.44 e-4

Stig-masterol Ratio 5-Avenasterol Sitosterol Total Ratio

5.64 e-4 L. goreensis 9.29 e-4 79.8 e-5 (100%) 3.74 4.75 e-4 e-4 4.39 5.64 e-5 e-4 7.95 79.8 e-4 9.29 1.00:1.68 3.74 e-5 4.39 e-4 7.95 e-5 79.8

24.5 0.36 3.30 36.0

1.00:1.68

Table X - Statistical analysis of the results from Table IX Statistics

6.44 e-4 Mean 9.34 e-4 63.6 e-5 4.52 5.44 4.40 e-4 6.44 8.14 e-4 e-5 63.6 e-4 9.34 4.52 e-5 4.40 e-4 8.14 e-5 63.6

A. monroviae

L. goreensis

1.00 rxy 2 1.00 from Table IX rxy X - Statistical analysis of the results Table Rxy -0.00038 Statistics A. monroviae L. goreensis Mean 6.7756 11.4039 1.00 rSD xy 17.9252 30.1707 1.00 rCV xy2 % 265 265 -0.00038 R CxyA 0.00 Mean 6.7756 11.4039 IFE SD 17.9252 30.1707 Remark * CV % 265 265 * = results significantly different at n-2 and r = 0.01 0.00 CA IFE particularly in nervous tissue such as the white matRemark *

ter of brain, nerves, neural tissue and in spinal cord * = results significantly different at r = 0.01 occupied the [20]. Phosphatidylinositol (PIn-2orand PtdIns) third position in concentration in the two fish samples having concentration range of 35.0 mg/100g (7.90%) and 36.5 mg/100g (6.84%) in A. monroviae and L. goreensis respectively; the CV% was 2.95. PI is a negatively charged phospholipid. PI can be phosphorylated to form phosphatidylinositol phosphate (PIP), phosphatidylinositol bisphosphate (PIP2) and phosohatidylinositol trisphosphate (PIP3). PIP, PIP2 and PIP3 are collectively called phosphoinositides. Phosphoinositides play important roles in lipid signaling, cell signaling and membrane tracking [20]. Phosphatidylserine (PS) was less than 10% in each of the

samples with value range of 23.0 mg/100g (5.19%) down to 18.5 mg/100g (3.47%). PS has been shown to enhance mood in a cohort of young people during mental stress and to improve accuracy during tee-off by increasing the stress resistance of golfers. The US Food and Drug Administration (USFDA) had stated that consumption of PS may reduce the risk of dementia in the elderly [20]. A. monroviae would be better in this function than L. goreensis. Lysophosphatidylcholine was the least concentrated in both samples (10.9-18.2 mg/100g or 2.46-3.41%) and CV% of 35.6 being the highest varied phospholipid in the two samples. Partial hydrolysis of PC with removal of only one fatty acid yields a lysophosphatidylcholine. The report of Viswanathan Nair and Gopakumar [74] on lipid and fatty acid compositions of five species of lean fish, silver hew fish (Johnius argentatus), milk fish (Chanos chanos), pearl spot (Etroplus suratensis), cat fish (Pseudarius jella and Tachysurus sp) and three species of shell fish, mussel (Perna viridis), crab (Neptunus pelagicus) and fresh water prawn (Macrobrachium rosenbergii) showed that PC was the major phospholipid in all the samples studied. In lean fish, its proportion varied from 55.9 to 63.8 per cent and in shell fish, from 44.0 to 68.9 per cent of total phospholipids. PE content was the second highest component (except in fresh water prawn). Its proportion in lean fish varied from 14.9 to 21.7 per cent of total phospholipids. Fresh water prawn was notable for its very low content of phosphatidylethanolamine (8.6

Table XI - Phospholipid levels (mg/100 g) of muscle of A. monroviae and L. goreensis Phospholipid

A. monroviae

L. goreensis

Mean

SD

CV %

Cephalin (PE) Lecithin (PC) Ptd-L-Ser (PS) Lysophosphatidyl-choline PtdIns (PI) Total

131 (29.7%) 242 (54.8%) 23.0 (5.19%) 10.9(2.46%) 34.0 (7.90%) 443

54.9 (29.0%) 305 (57.2%) 18.5 (3.47%) 18.2 (3.41%) 36.5 (6.84%) 533

143 274 20.7 14.5 35.7 488

16.7 44.4 3.15 5.18 1.06 64.2

11.6 16.2 15.2 35.6 2.95 13.2

Ratio

1.00:1.21

PE = phosphatidylethanolamine; lecithin = phosphatigylcholine; PS = phosphatidylserine; PI = phosphatidylinositol.


135

Table XII - Statistical analysis of the results from Table XI Statistics rxy rxy2 Rxy Mean SD CV % CA IFE Remark

A. monroviae

88.5271 98.3921 111

L. goreensis

0.9986 0.9971 -5.4470

0.0535 0.9465 *

106.6783 124.7988 117

* = results significantly different at n-2 and r = 0.01

136

per cent). Phosphatidylserine, phosphatidylinositol and small quantities of lyso-derivatives of phosphatidylcholine and phosphatidylethanolamine were also present in the samples. The statistical analysis of the variances from Table XI is shown in Table XII. The rxy was positively high and significant; also the rxy2 was high. For every 1.00 mg/100g increase in the A. monroviae there was a corresponding value of -5.45 (Rxy) in L. goreensis. The CV% ranged as 111-117 with low CA and high IFE. The high value of IFE was an indication that the relationship in the phospholipids composition of the fish samples could be easily predicted. Also the correlation determined for all the standards: fatty acids, phospholipids and sterols all had values ranging as follows: 0.99833-0.99997 (fatty acids), 0.99909-0.99999 (phospholipids) and 0.999200.99994 (sterols); all the correlation values were greater than 0.95 which is the critical correlation for acceptance of these types of analytical results. This attested to the quality assurance of the determinations.

CONCLUSION The findings of this study showed that the samples contained unequal distribution of all parameters determined. Acanthurus monroviae > Lutjanus goreensis fish muscle in crude fat, n-6 PUFA, n-3 PUFA, MUFA + PUFA, AA/DGLA, EPSI, PUFA/SFA, where as the reverse was the case in SFA, MUFA, EPA/DHA, LA/ ALA, MUFA/SFA, n-6/n-3, sterols and phospholipids. Both samples were high in unsaturated fatty acids, moderate in energy production due to low levels of fatty acids, low in sterols (cholesterol being the only major sterol) but high in phospholipids. Significant differences were noted in the fatty acids composition, fatty acids as food source, sterols and phospholipids compositions between A. monroviae and L. goreensis.

REFERENCES [1] J. Murray, J. R. Burt, Advisory Note No. 38. The composition of fish. FAO in partnership with Support unit for International Fisheries and

Aquatic Research, SIFAR, 2001. [2] P. Simopoulos, The importance of the ratio of omega -6/omega-3 essential fatty acids. Biomed Pharmacother 56, 365-379 (2002). [3] P. Kris-Etherton, W.S. Harris, L.J. Appel, Fish oils, omega-3 fatty acids and cardiovascular disease. Arteriosclerosis, Thrombosis and Vascular Biology 23, 20-31 (2003). [4] H. Tapiero, G. Nguyen Ba, P. Couvreur, K.D. Tew, Polyunsaturated fatty acids (PUFA) and eicosanoids in human health and pathologies. Biomed Pharmacother 56, 215-222, (2002). [5] C.E. Roynette, P.C. Calder, Y.M. Dupertuis, N-3 polyunsaturated fatty acids and colon cancer prevention. Clinical Nutrition 23, 139-151, (2004). [6] A. Belluzi, n-3 and n-6 acids for the treatment of autoimmune disease. Eur. J. Lipid Sci. Technol. 103, 399-407 (2001). [7] A. Turkmen, M. Turkmen, Y. Tepe, I. Akyrt, Heavy metals in three commercially valuable fish species from Iskenderun Bay, Northern East Mediterranean Sea, Turkey. Food Chemistry 91, 167-172 (2005). [8] W.N. Eschmeyer (ed.), Catalog of fishes. Special publication of the C enter for Biodiversity Research and Information. California Academy of Sciences, San Francisco, California, USA (1998). [9] Federal Ministry of Science and Technology, Trawl Fishes of the Nigerian Continental Shelf (No.1). Compiled and Produced by Marine Research Division, Nigerian Institute of Oceanography and Marine Research of the Federal Ministry of Science and Technology, Victoria Island, Lagos, Nigeria (1975). [10] G.R. Allen, FAO species catalogue, vol. 6. Snappers of the world. An annotated and illustrated catalogue of lutjanid species known to date. FAO Fish. Synop. 125 (6): 208 p. Rome, FAO (1985). [11] A.O.A.C. Official Methods Of Analysis (18th Ed.). Ass. Of Official Analytical Chemists, Washington DC, USA, 920.39 (A), (2006). [12] A.O.A.C. Official Methods Of Analysis (18th Ed.). Ass. Of Official Analytical Chemists, Washington DC, USA, 969.33 and 996.06, (2006). [13] A.O.A.C. Official Methods Of Analysis (18th Ed.). Ass. Of Official Analytical Chemists, Washington DC, USA, 970.51, (2006). [14] R.K. Raheja, C. Kaur, A. Singh, I.S. Bhatia, New colorimetric method for the quantitative estimation of phospholipids without acid digestion. Journal of Lipid Research 14, 695-687 (1973). [15] A.A. Paul, D.A.T. Southgate, McCance and Widdowson’s The Composition of Foods (4th Ed). Her Majesty’s Stationery Office, London, (1978). [16] H. Greenfield, D.A.T. Southgate, Food compo-


sition data: production, management and use. FAO, Rome, (2003). [17] R.A. Oloyo, Fundamentals of research methodology for social and applied sciences. ROA Educational Press, Ilaro, Nigeria (2001). [18] E.I. Adeyeye, M.A. Oyarekua, Lipid profile of the skin and muscle of freshwater sardine (Pellenula afzeliusi): nutritional/dietary implications. Bangladesh J. Sci. Ind. Res. 46 (4), 523-532 (2011). [19] E.I. Adeyeye, A.J. Adesina, M.C. Ginika, H.E. Aiyo, Great barracuda: its skin and muscle fatty acids, phospholipids and zoosterols compositions. Int. J. Chem. Sci. 5 (1), 18-28 (2012). [20] E.I. Adeyeye, Levels of fatty acids, phospjolipids and sterols in the skin and muscle of tilapia (Oreochromic niloticus) fish. Riv. Ital. Sostanze Grasse 83 (1), 46-55 (2011). [21] E.I. Adeyeye, S. Owokoniran, F.E. Popoola, R.O. Akinyeye, Fatty acids, phospholipids and sterols levels of the skin and muscle of Tongue sole fish. Pak. J. Sci. Ind. Res. Ser. A: Phys. Sci. 54 (3), 140-148 (2011). [22] G.M. Wardlaw, Contemporary nutrition: issues and insights (5th Ed.). McGraw-Hill, Boston, (2003). [23] A. Bonanome, S.M. Grundy, Effect of dietary stearic acid on plasma cholesterol and lipoprotein levels. New England J. Med. 318, 12441248 (1988). [24] J.F. Mead, M. Kayama, Lipid metabolism in fish. In M.E. Stansby (Ed.), Fish oils, 289-299: Avi Publ. Co., Westport, Conn. (1967). [25] K.C. Hayes, Dietary fat and heart health: in search of the ideal fat. Asia Pacific J. Clin. Nutr. 11 (Suppl.), S394-S400 (2002). [26] M.G. Enig, S. Fallon, The truth about saturated fats. (Proven Health Benefits of Saturated Fats) From: Nourishing traditions: the cookbook that challenges politically correct nutrition and the diet dictocrats by Fallon S. with Enig M.G. (New Trends Publishing 2000, www.newtrendspublishing.com 877-707-1776), 1-39 (2000). [27] N. Weber, Klaus-Dieter Richter, E. Schilte, K. D. Mukherjee, Petroselinic acid from dietary triacyglycerol reduces the concentration of arachidonic acid in tissue lipids of rats. J. Nutr. 125, 1563-1568 (1995). [28] H. Mohrhauer, J.J. Bahm, J. Seufert, R.T. Holman, Metabolism of linoleic acid in relation to dietary monoenoic fatty acids in the rat. J. Nutr. 91 (4), 521-527 (1967). [29] P. Nestel, P. Clifton, M. Noakes, Effects of increasing dietary palmitoleic acid compared with palmitic and oleic acids on plasma lipids of hypercholesterolemic men. J. Lipid Res. 35, 656662 (1994). [30] S.M. Grundy, Influence of stearic acid on cholesterol metabolism relative to other long-chain

fatty acids. Am J. Clin. Nutr. 60 (Suppl.), 986S990S (1994). [31] E. Christensen, T.A. Hagve, B.O. Christophersen, The Zellweger syndrome: deficient chainshortening of erucic acid [22:1(n-9)]. Biochem. Biophy. Acta 959 (2), 134-142 (1988). [32] J.R. Sargent, K. Coupland, R. Wilson, Nervonic acid and demyelinating diseases. Med. Hypotheses 42, 237-242 (1994). [33] M. Rasmussen, A.B. Moser, J. Borel, S. Khangoora, H.W. Moser, Brain, liver and adipose tissue erucic and very-long-chain fatty acids levels in adrenoleukodystrophy patients treated with glyceryl tri-erucate and trioleate oils (Lorenzo’s oil). Neurochem. Res. 19, 1073-1082 (1994). [34] M.S. Whetsell, E.B. Rayburn, J.D. Lozier, Human health effects of fatty acids in beef. PastureBased Beef Systems for Appalachia. Extension Service, West Virginia University, (2003). [35] R.S. Lord, J.A. Bralley, Copyright 2001 Metametrix Inc. Metametrix is a service mark registered with the United States Patent and Trademark office, (2001) (www.metametrix.com) [36] N.B. Cater, M.A. Denke, Behenic acid is a cholesterol-raising saturated fatty acid in humans. Am. J. Clin. Nutr. 73 (1), 41-44 (2001). [37] W.E.M. Lands, Fish and human health. Academic Press, Orlando, (1986). [38] M.E. Stansby, Nutritional properties of fish oil for human consumption-early developments. In: M.E. Stansby (Editor), Fish Oils in Nutrition. Van Nostrand Reinhold, New York, 268-288, (1990a). [39] M.E. Stansby, Nutritional properties of fish oil for human consumption-modern aspects. In: M.E. Stansby (Editor), Fish Oils in Nutrition. Van Nostrand Reinhold, New York, 289-308, (1990b). [40] G.M. Pigott, B.B. Tucker, Science opens new horizons for marine lipids in human nutrition. Food Rev. Int. 3, 105-138 (1897). [41] P. Singer, Was sind, wie wirken Omega-3-Fettsäuren? Umschau Zeitschriftenverlag, Frankfurt am Main, 197, (1994). [42] Statistisches Jahrbuch für die Bundesrepublik Deutschland. Statistisches Bundesamt, Wiesbaden, 764, (1992). [43] J. Dyerberg, Observations on populations in Greenland and Denmark. In: S.M. Barlow and M.E. Stansby (Editors), Nutritional Evaluation of Long Chain Fatty Acids in Fish Oil. Academic Press, New York, 245-262, (1982). [44] W. Steffens, Effects of variation in essential fatty acids in fish feeds on nutritive value of freshwater fish for humans. Aquaculture. 151, 97-119 (1997). [45] M. Yamada, K. Hayashi, Fatty acid composition of lipids from 22 species of fish and mollusk. Bull. Jpn. Soc. Sci. Fish 41, 1143-1152 (1975).


137

138

[46] J.R. Sargent, R.J. Henderson, Lipid metabolism in marine animals. Biochem. Soc. Trans. 3, 296297 (1980). [47] J.D. Joseph, Fatty acid composition of commercial menhaden (Brevoortia spp.) oils: 1982 and 1983. Mar. Fish. Rev. 47 (3), 30-37 (1985). [48] K. Yamada, K. Kobayashi, Y. Yone, Conversion of linolenic acid to ω3-highly unsaturated fatty acids in marine fishes and rainbow trout. Bull. Jpn. Soc. Fish. 46, 1231-1233 (1980). [49] A.M. Nelson, Diet therapy in coronary diseaseEffects on mortality of high protein, high seafood, fat controlled diet. Geriatries 27, 103-116 (1972). [50] D. Kromhout, E.B. Bosschieter, Corde Lezenne Coulander, The inverse relation between fish consumption and 20-year mortality from coronary heart disease. N. Engl. J. Med. 312, 12061209 (1985). [51] H.O. Bang, J. Dyerberg, Plasma lipids and lipoproteins in Greenlandic West Coast Eskimos. Acta Med. Scand. 192, 85-94 (1972). [52] A. Hirai, T. Terano, H. Saito, Y. Tamura, S. Yoshida, Clinical and epidemiological studies of eicosapentaenoic acid in Japan. In: W.E.M. Lands (Editor), Proceedings of AOAC Short Course on Polyunsaturated Fatty Acids and Eicosanoids. Am. Oil Chem. Soc., Champaign, Illinois, 9-24, 1987. [53] R.G. Ackman, Fatty acid composition of fish oils. In: S.M. Barlow and M.E. Stansby (Editors), Nutritional Evaluation of Long Chain Fatty Acids in Fish Oils. Academic Press, London, 25-88, 1982. [54] B. Durie, Proceedings of a symposium on MAXEPA research. Br. J. Clin. Pract. 38 (Suppl.31), 1-30 (1984). [55] A. Leaf, P.C. Weber, Cardiovascular effects of n-3 fatty acids. N. Engl. J. Med. 318, 549-557 (1988). [56] P. Nestel, D. Topping, J. Marsh, S. Wong, H. Barrett, P. Roach, B. Kamboris, Effects of polyenoic fatty acids n-3 on lipid and lipoprotein metabolism. In: W.E.M. Lands (Editor), Proceedings of AOAC Short Course on Polyunsaturated Fatty Acids and Eicosanoids. Am. Oil Chem. Soc., Champaign, Illinois, 233-237, (1987). [57] G. Honatra, Dietary fats and arterial thrombosis. Haemostasis 2, 21-52 (1974). [58] J.E. Kinsella, Possible mechanisms underlying the effects of n-3 polyunsaturated fatty acids. Omega-3 News 5, 1-5 (1990). [59] WHO/FAO, Fats and oil in human nutrition. Report of a joint consultation: FAO Food and Nutrition Paper 57. WHO/FAO, Rome, (1994). [60] Canadian Government Publishing Center, Nutrition Recommendations: The report of the Scientific Review Committee. Canadian Government Publishing Center, Ottawa, Canada, (1990).

[61] J.M. Berg, L. John, L. Typoczko, S. Lubert, Biochemistry (6th edition). W.A. Freeman and Company, New York, (2007). [62] P. Benatti, G. Peluso, R. Nicolai, M. Calvani, Polyunsaturated fatty acids: biochemical, nutritional and epigenetic properties. J. Am. Coll. Nutr. 23 (4), 281-302 (2004). [63] G. Hornstra, Essential fatty acids, pregnancy and complications: a rountable discussion. In: A. Sinclair and R. Gibson (Editors), Essential fatty acids and eicosanoids. Am. Oil Chem. Soc., champaign, 177-182, (1992). [64] M. Neuringer, W.E. Connor, D.S. Lin, L. Barstad, S. Luck, Biochemical and functional effects of prenatal and postnatal omega-6 fatty acid deficiency on retina and brain in rhesus monkeys. Proc. Natl. Acad. Sci. USA 83, 4021-4025 (1986). [65] C.A. Daley, A. Abbott, P.S. Dovie, G.A. Nader, S. Larson, Grass fed versus grain fed beef: fatty acid profiles, antioxidant content and taste. Nutr. J. 9, 10-21 (2010). [66] S.V. Souci, W. Fachmann, H. Kraut, Food composition and nutrition tables 1989/1990. Wissenschaftliche Verlagsgesellschaft mbH Stuttgart, (1990). [67] Royal Society, Metric units, conversion factors and nomenclature in nutritional and food sciences. Report of the subcommittee on metrication of the British National Committee for Nutritional Sciences, London, (1972). [68] E.N. Whitney, C.B. Cataldo, S.R. Rolles, Understanding normal and clinical nutrition (4th edition). West Publishing Company, New York, (1994). [69] P.J. Jones, Regulation of cholesterol biosynthesis by diet in humans. Am. J. Clin. Nutr. 66 (2), 438-446 (1997). [70] E.M. Cranton, J.P. Frackelton, Free radical pathology in age associated diseases:treatment with EDTA chelation, nutrition and antioxidants. Journal of Holistic Medicine (Spring/Summer), 6-37 (1984). [71] H. Engelberg, Low serum cholesterol and suicide. Lancet 339, 727-728 (1992). [72] R.B. Alfin-Slater, L. Aftergood. Lipids, modern nutrition in health and disease (6th edition). In: R.S. Goodhart, M.E. Shils (Editors), Lea and Febiger, Philadelphia, 134, (1980). [73] Addis, Paul, Food and Nutrition News (March/ April) 62 (2), 7-10 (1990). [74] P.G. Viswanathan Nair, K. Gopakumar, Lipid and fatty acid composition of fish and shell fish. J. Food Sci. Technol. 21 (Nov/Dec.), 389-392 (1984).

Received, February 26, 2014 Accepted, June 4, 2014
