Principal Fatty Acids of Depot Fat and Milk Lipids from Harp Seal (Pagophilus groenlandica) and Hooded Seal (Cystophora cristata)

1968 ◽  
Vol 25 (11) ◽  
pp. 2419-2426 ◽  
Author(s):  
P. M. Jangaard ◽  
P. J. Ke
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Unsaturated Fatty Acids ◽  
Gas Liquid Chromatography ◽  
Highly Unsaturated Fatty Acids ◽  
Hooded Seal ◽  
Cystophora Cristata ◽  
Milk Lipids ◽  
Iodine Values ◽  
Fatty Acid Compositions

The fatty acid compositions of six samples of depot fat taken from harp seals (Pagophilus groenlandica), ranging in age from 1 to 2 days to adult, and a sample of milk lipids, were determined by gas–liquid chromatography (GLC). Three depot fat samples taken from hooded seals (Cystophora cristata), a sample of milk lipids from this species, and commercial seal oils from 4 years' production were similarly analyzed.No significant differences could be found between the composition of the milk lipids and the depot fat of the harp seals at the different ages, other than slightly lower iodine values in the younger animals (avg 140.6 vs. 148.9). The lipid samples from hooded seals had low iodine values (107–127) and correspondingly lower concentration of highly unsaturated fatty acids. The ratio of the fatty acids 22:5ω3/22:6ω3 could be used to differentiate between depot fat from harp seals (ratio 0.51–0.74) and that from hooded seals (ratio 0.25–0.42) in the samples analyzed.Commercial oils, which consist essentially of oil from harp seals, were similar in composition to oil prepared from this species alone.No difference could be found in the iodine values or fatty acid compositions of samples taken from various parts of the animal or from samples representing a cross section of blubber.

Marine Phytoplankter Fatty Acids

1968 ◽  
Vol 25 (8) ◽  
pp. 1603-1620 ◽  
Author(s):  
R. G. Ackman ◽  
C. S. Tocher ◽  
J. McLachlan
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Chain Polyunsaturated Fatty Acid ◽  
Gas Liquid Chromatography ◽  
Specific Fatty Acid ◽  
Unicellular Algae ◽  
Total Fatty Acids ◽  
Filter Feeders ◽  
Iodine Values ◽  
Fatty Acid Compositions

Twelve species of marine unicellular algae have been cultured under comparable conditions and the total fatty acids determined by gas–liquid chromatography. Some specific fatty acid relationships paralleling taxonomic groupings were detected but generally individual fatty acids within various algal classes showed large relative variations. The four Bacillariophyceae examined were notable for fatty acid compositions giving iodine values <150, whereas in eight other classes the iodine values were all approximately 200. It is suggested that 5,8,11,14,17-eicosapentaenoic acid, found to be a common algal longer-chain polyunsaturated fatty acid, is characteristically deposited in the lipids of filter-feeders ingesting unicellular algae.

scholarly journals The same rat Δ6-desaturase not only acts on 18- but also on 24-carbon fatty acids in very-long-chain polyunsaturated fatty acid biosynthesis

2002 ◽  
Vol 364 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Sabine D'ANDREA ◽  
Hervé GUILLOU ◽  
Sophie JAN ◽  
Daniel CATHELINE ◽  
Jean-Noël THIBAULT ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acid ◽  
Unsaturated Fatty Acids ◽  
Fatty Acid Biosynthesis ◽  
Chain Polyunsaturated Fatty Acid ◽  
Acid Biosynthesis ◽  
Highly Unsaturated Fatty Acids ◽  
Long Chain ◽  
Δ6 Desaturase

The recently cloned Δ6-desaturase is known to catalyse the first step in very-long-chain polyunsaturated fatty acid biosynthesis, i.e. the desaturation of linoleic and α-linolenic acids. The hypothesis that this enzyme could also catalyse the terminal desaturation step, i.e. the desaturation of 24-carbon highly unsaturated fatty acids, has never been elucidated. To test this hypothesis, the activity of rat Δ6-desaturase expressed in COS-7 cells was investigated. Recombinant Δ6-desaturase expression was analysed by Western blot, revealing a single band at 45kDa. The putative involvement of this enzyme in the Δ6-desaturation of C24:5n-3 to C24:6n-3 was measured by incubating transfected cells with C22:5n-3. Whereas both transfected and non-transfected COS-7 cells were able to synthesize C24:5n-3 by elongation of C22:5n-3, only cells expressing Δ6-desaturase were also able to produce C24:6n-3. In addition, Δ6-desaturation of [1-14C]C24:5n-3 was assayed invitro in homogenates from COS-7 cells expressing Δ6-desaturase or not, showing that Δ6-desaturase catalyses the conversion of C24:5n-3 to C24:6n-3. Evidence is therefore presented that the same rat Δ6-desaturase catalyses not only the conversion of C18:3n-3 to C18:4n-3, but also the conversion of C24:5n-3 to C24:6n-3. A similar mechanism in the n-6 series is strongly suggested.

FATTY ACID COMPOSITION OF NORMAL MINK TISSUES

1966 ◽  
Vol 44 (2) ◽  
pp. 179-185 ◽  
Author(s):  
B. L. Walker ◽  
V. F. Lishchenko
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Essential Fatty Acids ◽  
Methyl Esters ◽  
Dietary Factors ◽  
Gas Liquid Chromatography ◽  
Healthy Female ◽  
Kidney Liver ◽  
Layer Chromatography ◽  
Fatty Acid Compositions

Lipids, extracted from the adrenals, brain, erythrocytes, heart, kidney, liver, plasma, and spleen of normal healthy female mink, were transesterified with 1% sulphuric acid in methanol, and the resulting methyl esters were analyzed by gas–liquid chromatography after purification by thin-layer chromatography. All of the tissues examined contained higher concentrations of unsaturated than of saturated acids, the highest levels of unsaturated acids occurring in the lipids of heart, adrenals, and plasma, and of the essential fatty acids (ω6 series, with six carbon atoms after last double bond) in plasma, erythrocyte, and kidney lipids. The fatty acid compositions of mink tissues resemble those reported in the literature for the rat; detailed comparisons are not possible because of the known influence of dietary factors on tissue fatty acids.

600. Further observations on the volatile compounds associated with oxidized flavour in skim milk

1955 ◽  
Vol 22 (3) ◽  
pp. 345-348 ◽  
Author(s):  
D. A. Forss ◽  
E. G. Pont ◽  
W. Stark
Keyword(s):  
Fatty Acids ◽  
Volatile Compounds ◽  
Previous Investigation ◽  
Unsaturated Fatty Acids ◽  
Skim Milk ◽  
Highly Unsaturated Fatty Acids ◽  
Milk Lipids

The C6–C11 2,4–dienals have been identified in distillates from skim milk with oxidized flavour. The C4–C11 2–enals were isolated from the same distillates in a previous investigation. The most abundant individual compounds in the two groups were 2–octenal, 2–nonenal, 2–4–heptadienal and 2,4–nonadienal. These compounds when flavour–tested in skim milk in dilutions of 10–7–10–9 closely resembled oxidized (cardboard) flavour. It is concluded that they are the main constituents of this flavour defect and that they originate from the oxidation of the more highly unsaturated fatty acids in milk lipids.

Biochemical Implications of Seasonal Trends in the Iodine Values and Free Fatty Acid Levels of Commercially Produced Atlantic Coast Herring Oils

1970 ◽  
Vol 27 (10) ◽  
pp. 1669-1683 ◽  
Author(s):  
R. G. Ackman ◽  
C. A. Eaton
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Nova Scotia ◽  
Atlantic Coast ◽  
Relative Proportion ◽  
Short Term ◽  
Iodine Values ◽  
Seasonal Decline ◽  
Fatty Acid Compositions

Annual surveys of commercial herring oils produced in summer and fall off southwestern Nova Scotia and in winter and spring off southwestern Newfoundland showed iodine values (IV) mostly within the range 135 to 105 in both locations for the years 1965–70. Two systematic trends in IV with season were detected. The first extended uniformly over the whole of each fishery season and was limited to no more than ± 5 IV units. It is believed to represent the influence of long-term average environmental conditions that may vary from year to year and that establish the basic fatty acid compositions of the fish entering the fishery. The second was observed as a seasonal decline, over 2–3 months, of 20 IV units in the Nova Scotia fishery, and of 10 IV units in the Newfoundland fishery. It is proposed that this short-term effect follows from an increase in the relative proportion of the low-density, long-chain, monoethylenic fatty acids characteristic of clupeid oils that could decrease residual fat density at a time of general fat depletion and corresponding density increase for the fish as a whole.Free fatty acids (FFA) in freshly produced oils were also examined. In both fisheries % FFA seldom exceeded 1 and under optimum conditions the % FFA were consistently about 0.2–0.3. Annual seasonal % FFA effects were apparently restricted to an increase in April in the Newfoundland fishery associated with high IV oils of a pink colour denoting heavy spring feeding.

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