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1.
Total lipid, phospholipid, and FA composition and distribution of FA between polar lipids (PL) and neutral lipids (NL) were
investigated in the boreal soft coral Gersemia rubiformis from the Bering Sea. The total lipids were mostly hydrocarbons and waxes (33.7%) and PL (33.1%). The content of monoalkyldiacylglycerols
(9.7%) exceeded the content of TAG (6.7%). PC and PE constituted 31.4% and 25.6% of total phospholipids, respectively. Principal
FA were 16∶0, 16∶1n−7, 18∶0, 18∶1n−9, 18∶1n−7, 20∶1n−7, 20∶4n−6, 20∶4n−3, 20∶5n−3 22∶5n−3, 22∶6n−3, 24∶5n−6, and 24∶6n−3.
Most n−6 PUFA (52% of total FA) were associated with the PL fraction; this was especially true for arachidonic and tetracosapentaenoic
acids. The NL were enriched with mono-, di-, trienoic, and n−3 PUFA. The variation in EPA levels in both NL and PL suggests
an origin of this acid from lipids of diatoms consumed by the corals. 相似文献
2.
The lipid and FA composition of the total lipids of the pearl oyster Pinctada fucata martensii, in different seasons and in different areas, were analyzed to clarify its lipid physiology and to estimate the possible
influence of its prey phytoplankton. TAG and sterols were the major components in the neutral lipids in all conditions, whereas
high levels of phospholipids (PE and PC) were found in the polar lipids. The major FA in the TAG in all samples were 14∶0,
16∶0, and 18∶0 as saturated FA (saturates); 16∶1n−7, 18∶1n−9, and 18∶1n−7 as monoenoic FA (monoenes); and 20∶4n−6 (arachidonic
acid: AA), 20∶5n−3 (EPA), and 22∶6n−3 (DHA) as PUFA. The major components found in the polar lipids were 16∶0 and 18∶0 as
saturates; 22∶2n−9, 15 and 22∶2n−7, 15 as non-methylene-interrupted dienes (NMID), and AA, 22∶3n−6, 9, 15, EPA, and DHA as
PUFA. Although it is a marine animal, characteristically high levels of AA were found in both the TAG and phospholipids. This
result suggests that lipids of P. fucata may be influenced by those of its phytoplanktonic prey. The increase in levels of NMID from TAG to PE with a decrease in
those of monoenes suggests that the tissues of this species are able to biosynthesize only the less unsaturated PUFA, such
as NMID. In particular, NMID derivatives are considered to be biosynthesized in the PE; thus, they might play a particular
role in the membrane, because NMID were characteristically localized only in the PE. 相似文献
3.
The FA composition of Fasciola hepatica 12 kDA purified native FA-binding protein (nFh12), a candidate vaccine against fascioliasis, is described. The FA chain lengths ranged between 12 and 24 carbons. The
principal FA were 16∶0 18∶1n−9, 18∶0, 20∶4n−6, and 20∶1n−9. The acids 16∶0, 18∶1n−9, and 18∶0 comprised over half the FA that
were bound to the whole FA-binding protein. Small amounts (1.0–2.8%) of isoanteiso methyl-branched FA also were characterized. Forty-one different FA were identified in extracts of the adult flukes, with
the three most abundant FA also being 16∶0, 18∶1n−9, and 18∶0. A similar proportion of saturated vs. unsaturated FA was observed
between the whole extract from F. hepatica and the nFh12 protein. However, the n−3/n−6 ratio of PUFA was significantly different, being 1.2 in the whole extract vs. 9.6 in the
nFh12 protein complex. The nFh12 protein binds more n−5, n−6, and n−7 PUFA and less n−3 and n−9 PUFA than the whole extract. In addition, cholesterol
(56%), sitosterol (36%), and fucosterol (8%) also were bound to the nFh12 protein complex. 相似文献
4.
The health benefits of long-chain n−3 PUFA (20∶5n−3 and 22∶6n−3) depend on the extent of incorporation of these FA into plasma
and tissue lipids. This study aimed to investigate the effect of the background dietary fat (saturated, monounsaturated, or
n−6 polyunsaturated) on the quantitative incorporation of dietary 18∶3n−3 and its elongated and desaturated products into
the plasma and the liver lipids of rats. Female weanling Wistar rats (n=54) were randomly assigned to six diet groups (n=9). The fat added to the semipurified diets was tallow (SFA), tallow plus linseed oil (SFA-LNA), sunola oil (MUFA), sunola
oil plus linseed oil (MUFA-LNA), sunflower oil (PUFA), or sunflower oil plus linseed oil (PUFA-LNA). At the completion of
the 4-wk feeding period, quantitative FA analysis of the liver and plasma was undertaken by GC. The inclusion of linseed oil
in the rat diets increased the level of 18∶3n−3, 20∶5n−3, and, to a smaller degree, 22∶6n−3 in plasma and liver lipids regardless
of the background dietary fat. The extent of incorporation of 18∶3n−3, 20∶5n−3, and 22∶5n−3 followed the order SFA-LNA>MUFA-LNA>PUFA-LNA.
Levels of 22∶6n−3 were increased to a similar extent regardless of the type of major fat in the rat diets. This indicates
that the background diet affects the incorporation in liver and plasma FA pools of the n−3 PUFA with the exception of 22∶6n−3
and therefore the background diet has the potential to influence the already established health benefits of long-chain n−3
fatty acids. 相似文献
5.
The effects of clofibrate on the content and composition of liver and plasma lipids were studied in mice fed for 4 wk on diets
enriched in n−6 or n−3 polyunsaturated fatty acids (PUFA) from sunflower oil (SO) or fish oil (FO), respectively; both oils
were fed at 9% of the diet (dry weight basis). Only FO was hypolipidemic. Both oil regimes led to slightly increased concentrations
of phospholipids (PL) and triacylglycerols (TG) in liver as compared with a standard chow diet containing 2% fat. Clofibrate
promoted hypolipidemia only in animals fed SO. Its main effect was to enlarge the liver, such growth increasing the amounts
of major glycerophospholipids while depleting the TG. SO and FO consumption changed the proportion of n−6 or n−3 PUFA in liver
and plasma lipids in opposite ways. After clofibrate action, the PUFA of liver PL were preserved better than in the absence
of oil supplementation. However, most of the drug-induced changes (e.g., increased 18∶1n−9 and 20∶3n−6, decreased 22∶6/20∶5
ratios) occurred inrrespective of lipids being rich in n−6 or n−3 PUFA. The concentration of sphingomyelin (SM), a minor liver
lipid that virtually lacks PUFA, increased with the dietary oils, decreased with clofibrate, and changed its fatty acid composition
in both situations. Thus. oil-increased SM had more 22∶0 and 24∶0 than clofibrate-decreased SM, which was significantly richer
in 22∶1 and 24∶1. 相似文献
6.
The American marten (Martes americana) is a boreal forest marten with low body adiposity but high metabolic rate. The study describes the FA composition in white
adipose tissue depots of the species and the influence of food deprivation on them. American marten (n=8) were fasted for 2 d with 7 control animals. Fasting resulted in a 13.4% weight loss, while the relative fat mass was >25%
lower in the fasted animals. The FA composition of the fat depots of the trunk was quite similar to other previously studied
mustelids with 14∶0, 16∶0, 18∶0, 16∶1n−7, 18∶1n−9, and 18∶2n−6 as the most abundant FA. In the extremities, there were higher
proportions of monounsaturated FA (MUFA) and PUFA. Food deprivation decreased the proportions of 16∶0 and 16∶1n−7, while the
proportion of long-chain MUFA increased in the trunk. The mobilization of FA was selective, as 16∶1n−7, 18∶1n−9, and particular
n−3 PUFA were preferentially mobilized. Relative mobilization correlated negatively with the carbon chain length in saturated
FA (SFA) and n−9 MUFA. The Δ9 desaturation of SFA enhanced the mobilization of the corresponding MUFA, but the positional
isomerism of the first double bond did not correlate consistently with relative mobilization in MUFA or PUFA. In the marten,
the FA composition of the extremities was highly resistant to fasting, and the tail tip and the paws contained more long-chain
PUFA to prevent the solidification of lipids and to maintain cell membrane fluidity during cooling. 相似文献
7.
Recent studies have demonstrated that long-chain n−3 PUFA (LCn-3PUFA) are beneficial in reducing the risk of cardiac arrhythmias.
This study was conducted to determine the extent of incorporation of LCn-3PUFA into human atrium following supplementation
with a fish oil concentrate high in LCn-3PUFA. Volunteers preparing for coronary bypass surgery were randomized either to
the treatment group (n=8), receiving 6 g/d of fish oil concentrate (4.4 g of LCn-3PUFA), or the placebo group (n=9), receiving 6 g/d of olive oil for a minimum period of 6 wk. Blood samples were collected prior to commencement of treatment,
and preoperatively before bypass surgery. Atrial biopsies were obtained during surgery. The plasma and atrium samples were
analyzed by GC following trans-methylation to determine FA profile. Post-supplementation, the treatment group had significantly
higher plasma levels of 20∶5n−3, 22∶5n−3, and 22∶6n−3 than the placebo group. Analysis of the atrium total lipids revealed
a significant increase in the proportion of 20∶5n−3 following fish oil supplementation. There was no significant difference
in the concentration of 22∶5n−3 and 22∶6n−3 in the atrium total lipids; however, an upward trend was observed in subjects
receiving fish oil supplementation. In the phospholipid fraction of the atrium, both 20∶5n−3 and 22∶6n−3 increased, whereas
20∶4n−6 levels decreased. This study demonstrates for the first time that short-term supplementation with fish oil concentrate
results in significant incorporation of LNc-3PUFA with a concomitant depletion of the eicosanoid substrate (20∶4n−6) in the
human atrium. 相似文献
8.
Muscle tissue from the common two-banded sea bream Diplodus vulgaris L. originating from the Adriatic Sea, Croatia, was analyzed. The FA composition of neutral (TAG) and polar (PE, PC, PI/PS)
lipid classes was determined, as well as the lipid and water contents during winter and summer periods. Both the total lipid
and water contents were higher in the winter period. We identified 16 different FA. The major constituents of the total FA
in both seasons were saturates: palmitic (16∶0) and stearic acids (18∶0); monoenes: oleic (18∶1n−9) and palmitoleic acids
(16∶1n−7); and polyunsaturates: arachidonic acid (20∶4n−6), EPA (20∶5n−3), and DHA (22∶6n−3), but their amounts and ratios
differed significantly between the two seasons and between lipid fractions. The FA composition showed a noticeable pattern
of seasonality that reflected fluctuations mainly in TAG. The diminution of the monounsaturated FA content in the summer was
clearly followed by an increase in PUFA content. Diplodus vulgaris is a good source of natural n−3 PUFA and would therefore be suitable for inclusion in highly unsaturated low-fat diets. 相似文献
9.
Positional specificity of gastric hydrolysis of long-chain n−3 polyunsaturated fatty acids of seal milk triglycerides 总被引:1,自引:0,他引:1
Long-chain n−3 polyunsaturated fatty acids (n−3 PUFA) of marine oils are important dietary components for both infants and
adults, and are incorporated into milks following maternal dietary intake. However, little is known about the hydrolysis of
these PUFA from milk triglycerides (TG) by lipases in suckling young. Seals, like humans, possess gastric lipase; however,
the milk lipids of seals and sea lions are almost devoid of the readily hydrolyzable medium-chain fatty acids, and are characterized
by a large percentage (10–30%) of n−3 PUFA. Gastric hydrolysis of milk lipids was studiedin vivo in suckling pups of three species (the California sea lion, the harp seal and the hooded seal) in order to elucidate the
actions and specificity of gastric lipases on milk TG in relation to fatty acid composition and TG structure. Regardless of
milk fat content (31–61% fat) or extent of gastric hydrolysis (10–56%), the same fatty acids were preferentially released
in all three species, as determined by their relative enrichment in the free fatty acid (FFA) fraction. In addition to 16∶1
and 18∶0, these were the PUFA of 18 carbons and longer, except for 22∶6n−3. Levels of 20∶5n−3 were most notably enriched in
FFA, at up to five times that found in the TG. Although 22∶6n−3 was apparently also released from the TG (reduced in the diglyceride),
it was also notably reduced in FFA. Positional analysis of milk TG based on the products of Grignard hydrolysis revealed that
these PUFA, including 22∶6n−3, were preferentially esterified at the α-position of the TG, and that the fatty acids not released
during gastric hydrolysis were located at thesn-2 position. The extreme reduction of 22∶6n−3 and enrichment of 20∶5n−3 in FFA is discussed. Results from this study are consistent
with reports that gastric lipase acts stereo-specifically to release fatty acids at the α-positions (sn−3,sn−1). We conclude that the n−3 PUFA in milk are efficiently hydrolyzed by gastric lipase and that this has important implications
for digestion of milks enriched in PUFA by neonates in general.
Based on a paper presented at the Symposium on Milk Lipids held at the AOCS Annual Meeting, Baltimore, MD, April 1990; part
of this work is from the doctoral dissertation by S.J.I., University of Maryland, 1988. 相似文献
10.
Supercritical fluid extracts of New Zealand green-lipped mussels (NZGLM) have been suggested to have therapeutic properties
related to their oil components. The large number of minor FA in NZGLM extract was characterized by a GC-CIMS/MS method that
excels at identification of double-bond positions in FAME. The extract contained five major lipid classes: sterol esters,
TAG, FFA, sterols, and polar lipids. The total FA content of the lipid extract was 0.664 g/mL. Fifty-three unsaturated FA
(UFA) were fully identified, of which 37 were PUFA, and a further 21 UFA were detected for which concentrations were too low
for assignment of double-bond positions. There were 17 saturated FA, with 14∶0, 16∶0, and 18∶0 present in the greatest concentration.
The 10 n−3 PUFA detected included 20∶5n−3 and 22∶6n−3, the two main n−3 FA; n−3 PUFA at low concentrations were 18∶3, 18∶4,
20∶3, 20∶4, 21∶5, 22∶5, 24∶6, and 28∶8. There were 43 UFA from the n−4, n−5, n−6, n−7, n−8, n−9, n−10, n−11 families, with
16∶2n−4, 16∶1n−5, 18∶1n−5, 18∶2n−6, 20∶4n−6, 16∶1n−7, 20∶1n−7, 16∶1n−9, 18∶1n−9, and 20∶1n−9 being the most abundant. In general,
we estimated that FAME concentrations greater than 0.05% (w/w) were sufficient to assign double-bond positions. In total,
91 FA were detected in an extract of the NZGLM, whereas previous studies of fresh flesh from the NZGLM had reported identification
of 42 FA. These data demonstrate a remarkable diversity of NZGLM FA. 相似文献
11.
The purpose of this study was to assess the FA composition of both cholesteryl esters (CE) and phospholipids (PL) in maternal
plasma during pregnancy and at delivery and in umbilical plasma at birth. A longitudinal study of 32 normal pregnant women
was carried out with three cutoff points during pregnancy (first, second, and third trimester) and at delivery. Few significant
differences occurred in the FA profile of maternal CE: 18∶1n−9 increased, 18∶2n−6 dropped slightly, and 18∶3n−3 decreased
with progressing gestation. In maternal PL, long-chain highly unsaturated FA concentrations dropped and were replaced by saturated
FA as gestation progressed. Additionally, changes in saturated FA in PL occurred: Shorter-chain 16∶0 was higher whereas longer-chain
18∶0 was lower at delivery compared to early pregnancy. The FA profile of umbilical venous plasma was strikingly different
from that of maternal plasma at delivery. Cord plasma CE contained more saturated and monounsaturated FA than maternal CE.
The polyunsaturates 18∶2n−6 and 18∶3n−3 are lower in umbilical CE than in maternal CE whereas 20∶4n−6 and 22∶6n−3 are twice
as high in umbilical CE. Cord plasma PL have a higher content of long-chain highly unsaturated FA than maternal plasma PL
at delivery. In contrast to maternal plasma PL, 16∶0 was lower and longer-chain saturated FA were higher in cord plasma PL.
The FA profile of umbilical plasma at birth shows preferential accumulation of 20∶4n−6 and 22∶6n−3, with low concentrations
of 18∶2n−6 and 18∶3n−3 in CE and PL, indicating a preferential supply of the fetus with long-chain highly unsaturated FA needed
for fetal development. 相似文献
12.
Milkfat is a complex mixture of many diverse FA, some of which have demonstrated health benefits including anticancer properties.
Attempts are under way to enrich milkfats with long-chain n−3 PUFA and CLA. It has been recommended that the analysis of these
milkfats requires gas chromatography (GC) equipped with long, highly polar capillary columns. However, many analyses have
been reported using CARBOWAXTM type (polyethylene glycol) capillary columns, such as SUPELCOWAX 10, even though the separation characteristics of many of
the FA and their isomers present in milkfats have not been described in detail. This includes the isomers of CLA, cis- and trans-octadecenoic acid (18∶1), linoleic acid (18∶2n−6), and linolenic acid (18∶3n−3), and the long-chain PUFA. On the other hand,
the resolution of these FA and their isomers has been more fully described using the highly polar capillary columns, such
as CP Sil 88 and SP2560 because of the improved resolution obtained using these polar columns. The present study was undertaken
to characterize the separation of these FA present in milkfats using a 60-m SUPELCOWAX 10 column, to compare the results to
those from a 100-m CP Sil 88 column, and to determine if these two columns could possibly serve to complement each other for
the analysis of total milkfat. The advantages of the SUPELCOWAX 10 column were a better resolution of the short-chain saturated
from their monounsaturated FA (MUFA) analogs, and a complete separation of the α-linolenic (18∶3n−3) and eicosadecenoic acid
(20∶1) isomers. It also provided an alternative elution order of the linoleic (18∶2n−6), 18∶3n−3 and γ-linolenic (18∶3n−6)
acid isomers. On the other hand, the CP Sil 88 column provided a better resolution of the CLA isomers, MUFA, the isolated
cis and trans MUFA fractions, the PUFA, and many the 18∶2n−6 and 18∶3n−3 isomers. A complete analysis of milk lipids using the CP Sil 88
column required the prior separation of total FAME using silver ion-TLC. The results of the present study confirm that the
100-m highly polar capillary GC columns are mandatory for the analysis of milk lipids, and at best, the 60 m SUPELCOWAX 10
capillary column serves as a complementary GC column to provide different separations in certain regions based on its intermediate
polarity. 相似文献
13.
Lipid and fatty acid composition and energy partitioning during embryo development in the shrimp Macrobrachium borellii 总被引:2,自引:0,他引:2
Energy partitioning, composition of lipids and fatty acids, and their utilization by embryos were determined in the lecithotrophic
shrimp Macrobrachium borellii during seven development stages. The biochemical composition at stage I is represented by lipids, proteins, and carbohydrates,
with 29.3, 28.7, and 0.2% dry weight, respectively. The former two were identified as the major energy-providing components,
contributing 131 and 60 cal/100 mg egg, dry weight, respectively. The overall conversion efficiency (CE) was 45.0% (calculated
as percentage of vitelline energy transformed into embryonic tissues). Lipids were the most important energy reserve (CE 39.3%),
followed by proteins (CE 57.1%), both being simultaneously utilized during development while carbohydrates were synthesized
de novo (CE 587.5%). Variation in the lipid class composition of embryos and vitellus showed an accumulation of triacylglycerols
(TAG) and phospholipids (PL) up to stage IV, a more active accumulation and selective utilization phase (stages V and VI),
and a consumption and de novo synthesis period until hatching. Structural lipids (PL and cholesterol) and pigment astaxanthin were selectively conserved
in embryos, but TAG, hydrocarbons, and esterified sterols were preferentially depleted. Monounsaturated fatty acids (FA) were
the major group in TAG, whereas polyunsaturated FA (PUFA) were the major group in PL after organogenesis. Certain PUFA such
as 22∶6n−3 and 20∶5n−3 were selectively accumulated in PL. 相似文献
14.
Blubbers of four ringed seal subspecies from Lake Saimaa, Lake Ladoga, the Baltic Sea, and Spitsbergen were analyzed for very
long chain polyunsaturated fatty acids (VLCPUFA; >C22) using gas-liquid chromatography and gas chromatography/mass spectrometry. The VLCPUFA of the blubber oils were mainly n−3
polyunsaturated fatty acids—23∶5n−3, 24∶3n−3, 24∶4n−3, 24∶5n−3, 24∶6n−3, 26∶5n−3, 26∶6n−3, and 28∶7n−3. The largest VLCPUFA
components in all populations were 24∶5n−3 (0.1–0.2 wt% of total fatty acids) and 24∶6n−3 (0.1%), but 24∶4n−3 (0.1%) was also
prominent in the Baltic specimens. The blubber oils of the freshwater species contained considerably more 24∶4n−6 and 24∶5n−6
than the blubbers of the marine species. The differences among the VLCPUFA in these subspecies appear to be mainly due to
different dietary VLCPUFA. 相似文献
15.
The total lipid and fatty acid compositions of tissues and the stomach contents of three subtropical marine fish species,
subfamily Caesioninae, Caesio diagramma and C. tile, and family Siganidae Siganus canaliculatus, were investigated to clarify the differences between these species. Triacylglycerols (TAG) were the dominant depot lipids
of the three species, whereas wax esters were found as a minor component. In particular, muscle lipids were found to contain
mainly glycerol derivatives such as TAG and phospholipids. The major fatty acids identified in the three species were 16∶0,
18∶0, 18∶1n−9, and 22∶6n−3 (docosahexaenoic acid, DHA). In addition, noticeable levels of 16∶1n−7, 18∶1n−7, 20∶4n−6 (arachidonic
acid, AA), and 20∶5n−3 (eicosapentaenoic acid) were found. DHA was the most abundant polyunsaturated fatty acid (PUFA) in
the muscle and viscera lipids of the three species. The high DHA levels in the lipids of all the organs were found to be higher
than those of the lipid extracted from the stomach contents of the three fishes. In addition, the specimens of S. canaliculatus contained significantly higher levels of AA in its tissues than did the other two species. A high AA content is unusual since
such high levels of n−6 PUFA are rarely found in higher marine organisms. These levels may be due to its characteristic feeding
pattern, because S. canaliculatus prefer and mainly feed on seaweed, which often contains high amounts of n−6 PUFA, such as linoleic acid (18∶2n−6) and AA. 相似文献
16.
Indian diets comprising staples such as cereals, millets, and pulses provide 4.8 energy % from linoleic acid (18∶2n−6) but
fail to deliver adequate amounts of n−3 FA. Consumption of long-chain n−3 PUFA such as EPA (20∶5n−3) and DHA (22∶6n−3) is
restricted to those who consume fish. The majority of the Indian population, however, are vegetarians needing additional dietary
sources of n−3 PUFA. The present work was designed to use n−3 FA-enriched spray-dired milk powder to provide n−3 FA. Whole
milk was supplemented with linseed oil to provide α-linolenic acid (LNA, 18∶3n−3), with fish oil to provide EPA and DHA, or
with groundnut oil (GNO), which is devoid of n−3 PUFA, and then spray-dired. Male Wistar rats were fed the spray-dired milk
formulations for 60 d. The rats given formulations containing n−3 FA showed significant increases (P<0.001) in the levels of LNA or EPA/DHA in the serum and in tissue as compared with those fed the GNO control formulation.
Rats fed formulations containing n−3 FA had 30–35% lower levels of serum total cholesterol and 25–30% lower levels of serum
TAG than control animals. Total cholesterol and TAG in the livers of rats fed the formulations containing n−3 FA were lower
by 18–30% and 11–18%, respectively, compared with control animals. This study showed that spray-dried milk formulations supplemented
with n−3 FA are an effective means of improving dietary n−3 FA intake, which may decrease the risk factors associated with
cardiovascular disease. 相似文献
17.
The effects of dietary cis and trans α-linolenic acid (18∶3n−3) on the FA composition of plasma, red blood cell, and liver phospholipids were studied in newborn
piglets. Animals were fed for 14 d with one of three diets: a control diet (group A) containing cis 18∶3n−3 at a level of 2.0% of total FA, a diet (group B) in which a part of the 18∶3n−3 acid was isomerized (1.3% of cis 18∶3n−3 and 0.7% of trans 18∶3n−3), or a diet (group C) with 2.0% cis 18∶3n−3 and 0.7% trans 18∶3n−3. Feeding animals with diets containing trans 18∶3n−3 resulted in the presence of trans isomers of 18∶3n−3, trans isomers of EPA, and trans isomers of DHA in phospholipids; however, the level of total trans n−3 PUFA in tissues was less than 0.3% of total tissue FA. In group B, the reduction of dietary amounts of cis 18∶3n−3 was associated with a decrease in individual and total cis n−3 PUFA. In contrast, in group C there was no decrease in tissue n−3 PUFA despite the increased dietary level of trans 18∶3n−3. These results suggest that the isomerization of a part of dietary n−3 PUFA, leading to the reduction of their levels
in the diet, could induce a decrease in n−3 PUFA in phospholipids. The physiological effects of trans PUFA are not known and should be considered in future studies. 相似文献
18.
Masaki Kaneniwa Song Miao Chunhong Yuan Haruka Lida Yutaka Fukuda 《Journal of the American Oil Chemists' Society》2000,77(8):825-831
The lipid and fatty acid composition of muscle of 10 species of freshwater fish obtained from a market of Shanghai City was
examined. Total lipids (TL) ranged over 0.9–4.7% of muscle for all samples. The content of triacylglycerol (TG) in muscle
ranged over 0.2–3.4% and that of polar lipids (PL) was 0.5–1.3%. Differences of TL content were dependent on TG contents.
The predominant important fatty acids (>10% of the total fatty acids in TL) were 16∶0 and 18∶1n−9 with some 16∶1n−7, 18∶2n−6,
and 22∶6n−3. The polyunsaturated fatty acids (PUFA) content was 10.2–43.4%, and especially Chinese sea bass contained above
20% of 22∶6n−3 in the total fatty acids. There were higher levels of PUFA such as 20∶5n−3 and 22∶6n−3 in PL than in neutral
lipids. Muscle of the silver carp was stored at 20°C, and changes of lipid classes during storage were examined. Free fatty
acids increased, and PL decreased during storage. This phenomenon was inhibited by heating the muscle, suggesting that lipid
hydrolysis by phospholipase occurred in silver carp muscle. 相似文献
19.
Fatty acid composition of habitual omnivore and vegetarian diets 总被引:1,自引:0,他引:1
High-fat diets are implicated in the onset of cardiovascular disease (CVD), cancer, and obesity. Large intakes of saturated
and trans FA, together with low levels of PUFA, particularly long-chain (LC) omega-3 (n−3) PUFA, appear to have the greatest impact
on the development of CVD. A high n−6∶n−3 PUFA ratio is also considered a marker of elevated risk of CVD, though little accurate
data on dietary intake is available. A new Australian food composition database that reports FA in foods to two decimal places
was used to assess intakes of FA in four habitual dietary groups. Analysis using the database found correlations between the
dietary intakes of LC n−3 PUFA and the plasma phospholipid LC n−3 PUFA concentrations of omnivore and vegetarian subjects.
High meat-eaters (HME), who consumed large amounts of food generally, had significantly higher LC n−3 PUFA intakes (0.29 g/d)
than moderate meat-eaters (MME) (0.14 g/d), whose intakes in turn were significantly higher than those of ovolacto-vegetarians
or vegans (both 0.01 g/d). The saturated FA intake of MME subjects (typical of adult male Australians) was not different from
ovolacto-vegetarian intakes, whereas n−6∶n−3 intake ratios in vegetarians were significantly higher than in omnivores. Thus,
accurate dietary and plasma FA analyses suggest that regular moderate consumption of meat and fish maintains a plasma FA profile
possibly more conducive to good health. 相似文献
20.
The brain contains high levels of the long-chain n−3 FA DHA(22∶6n−3), mainly in the gray matter and synaptosomes. Adequate
intake of DHA is crucial for optimal nervous system function, particularly in infants. Supplementation of infant formulas
with DHA at levels similar to human breast milk is recommended for biochemical and functional benefits to neonates. We generated
transgenic mice that produce elevated levels of n−3 PUFA in their milk by expressing the Caenorhabditis elegans n−3 FA desaturase under the control of a lactation-induced goat beta-casein promoter. To examine the postnatal effects of
consuming the n−3-enriched milk, we compared the growth and brain and plasma FA composition of mouse pups raised on milk from
transgenic dams with those observed for pups raised on milk from nontransgenic dams. A significant decrease in arachidonic
acid (ARA, 20∶4n−6) and concomitant increases in n−3 PUFA were observed in the phospholipid fraction of transgenic mouse milk.
The n−6∶n−3 FA ratios were 4.7 and 34.5 for the transgenic and control milk phospholipid fractions, respectively. DHA and
DPA (22∶5n−6) comprised 15.1% and 2.8% of brain FA from weanling mice nursed on transgenic dams, as compared with 6.9% and
9.2% for weanling mice nursed on control dams, respectively. This transgenic mouse model offers a unique approach to disassociate
the effects and fetal programming resulting from a high n−6∶n−3 FA ratio gestational environment from the postnatal nutritional
effects of providing milk with differing n−6∶n−3 FA ratios. 相似文献