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1.
P. M. Kris-Etherton 《European Journal of Lipid Science and Technology》1993,95(12):448-452
We conducted two clinical studies to examine the effects of diets high in stearic acid and lauric + myristic acid on plasma lipids and lipoproteins of healthy young men. In the first study subjects (n = 15) were fed whole food diets high in cocoa butter, butter, olive oil and soybean oil. In the second study, subjects were fed diets very high in saturated fatty acids (> 20% of calories) that were high in either stearic acid (from cocoa butter or milk chocolate) or lauric + myristic acid (from butter). In the first study, cocoa butter elicited a neutral cholesterolemic effect, whereas the butter diet was hypercholesterolemic and the olive oil and soybean oil diets were hypocholesterolemic. In the second study, the diets high in stearic acid did not raise plasma total and LDL-cholesterol levels, whereas, as in the first study, butter was markedly hypercholesterolemic. Regression analyses performed on the individual data from these two clinical studies were conducted to establish the cholesterolemic effects of individual fatty acids. The bestfitting linear regression equations relating ΔTC (change in plasma total cholesterol) was: ΔTC = 2.3 ΔC14:0 + 3.0 ΔC16:0-0.8 ΔC18:0-1.0 ΔPUFA, where Δ fatty acid = change in intake expressed as percent of calories. This predictive equation separates stearic acid from the other long-chain saturated fatty acids and suggests that it has an independent cholesterol-lowering effect. In conclusion, stearic acid is a unique long-chain saturated fatty acid. 相似文献
2.
We studied the effect of four rapeseed oils with different fatty acid profiles on parameters implicated in the pathogenesis of atherosclerosis in humans in a model experiment with hamsters. The hamsters were divided into seven groups and fed a semi‐synthetic, cholesterol‐enriched diet (5 g/kg diet) containing 15% of the fat in question for a period of six weeks. The following rapeseed oils were used: (1) conventional rapeseed oil (6% saturated fatty acids [SFA], 64% monounsaturated fatty acids [MUFA], 18% linoleic acid [LA], 9% α‐linolenic acid [ALA]), (2) linoleic acid‐rich rapeseed oil (6% SFA, 61% MUFA, 28% LA, 2% ALA), (3) oleic acid‐rich rapeseed oil (6% SFA, 74% MUFA, 11% LA, 5% ALA), (4) myristic acid‐rich rapeseed oil (11% myristic acid, 35% SFA, 44% MUFA, 14% LA, 5% ALA). Sunflower oil, olive oil and lard were used as control fats. The concentrations of the lipids in the plasma, in the lipoprotein fractions and in the liver, the fatty acid composition of various tissues, the tocopherol status and the susceptibility of low‐density lipoproteins (LDL) to in vitro‐oxidation were determined. The concentrations of total cholesterol found in the plasma and in the LDL fraction and the ratios of LDL to HDL were similar after feeding the four different types of rapeseed oil, sunflower oil and olive oil. Lard produced the highest concentrations of cholesterol in plasma and the LDL fraction and the highest ratio of LDL to HDL. Feeding conventional, oleic acid‐ and myristic acid‐rich rapeseed oils resulted in markedly lower ratios of arachidonic to eicosapentaenoic acid in the lipids of the liver and the erythrocytes. This is considered beneficial for the formation of eicosanoids. The lag‐time before the onset of peroxidation of the LDL lipids, induced by copper ions, was not statistically significant between the seven hamster groups suggesting that the susceptibility of LDL to lipid peroxidation was similar after feeding all types of fat. Considering all parameters obtained in the used hamster model it is obvious that all four rapeseed oils are at least as favourable as olive oil or sunflower oil. 相似文献
3.
Bertram I. Cohen Erwin H. Mosbach Nariman Ayyad Shigeo Miki Charles K. McSherry 《Lipids》1992,27(7):526-532
We tested two hypotheses, i) whether the type and the amount of fat in the diet will affect the formation of cholesterol gallstones
in the hamsters, and ii) whether palmitic acid, a major fatty acid component of butterfat, can act as a potentiator of cholesterol
cholelithiasis in the hamster. Young, male golden Syrian hamsters (Sasco) were fed a semipurified diet containing casein,
corn starch, cellulose and cholesterol (0.3%) to which various types and amounts of fat (butterfat, olive oil, menhaden oil,
corn oil) were added. All diets contained 2% corn oil to supply essential fatty acids to the growing hamsters. No deaths or
illness occurred during the experiment. Animals fed the semipurified diet plus 4% butterfat (group 1) had a gallstone incidence
of 63%. Replacement of butterfat with either olive oil, corn oil or menhaden oil prevented the formation of cholesterol gallstones
entirely (groups 2–4). When total butterfat was increased from 4% to 8% (group 8), the incidence of cholesterol gallstones
increased to 80%. Substitution of 4% olive oil (group 5), corn oil (group 6), or menhaden oil (group 7) for the additional
4% butterfat significantly reduced gallstones to 35%, 45% and 30%, respectively. The replacement of 4% butterfat with 1.2%
palmitic acid gave the highest incidence of cholesterol gallstones (95%). These results suggest that butterfat (and one of
its components, palmitic acid) intensifies gallstone formation in this model whereas mono- and polyunsaturated fats act as
inhibitors of cholesterol cholelithiasis. A fatty acid, possibly palmitic acid, appears to act as lithogen in our model. 相似文献
4.
Maike Heuel Michael Kreuzer Christoph Sandrock Florian Leiber Alexander Mathys Moritz Gold Christian Zurbrügg Isabelle D. M. Gangnat Melissa Terranova 《Lipids》2021,56(4):423-435
Implementing insects, such as the black soldier fly larvae (BSFL), as animal feed commonly includes the previous removal of substantial amounts of fat. This fat may represent an as yet underutilized energy source for livestock. However, transfer of lauric and myristic acid, prevalent in BSFL fat and undesired in human nutrition, into animal-source foods like eggs may limit its implementation. To quantify this, a laying hen experiment was performed comprising five different diets (10 hens/diet). These were a control diet with soybean oil and meal and a second diet with soybean oil but with partially defatted BSFL meal as protein source. The other three diets were based on different combinations of partially defatted BSFL meal and fat obtained by two different production methods. Lauric acid made up half of the BSFL fat from both origins. Both BSFL fats also contained substantial amounts of myristic and palmitic acid. However, in the insect-based diets, the net transfer from diet to egg yolk was less than 1% for lauric acid, whereas the net transfer for myristic and palmitic acid was about 30% and 100%, respectively. The net transfer did not vary between BSFL originating from production on different larval feeding substrates. The results illustrate that hens are able to metabolize or elongate very large proportions of ingested lauric acid and myristic acid, which are predominant in the BSFL lipids (together accounting for as much as 37 mol%), such that they collectively account for less than 3.5 mol% of egg yolk fatty acids. 相似文献
5.
Saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) show different effects on the development of insulin resistance.
In this study, we compared the effect of dietary SFA and MUFA on the insulin signaling pathway in the skeletal muscle of a
type 2 diabetic animal model. Twenty-nine-week-old male Otsuka Long-Evans Tokushima fatty (OLETF) rats were randomly divided
into three groups and fed one of the following diets for 3 weeks; a normal chow diet, an SFA (lard oil) enriched or a MUFA
(olive oil) enriched high-fat diet. The vastus lateralis muscle was used for analyses. Insulin tolerance test showed improved
insulin sensitivity in rats fed the MUFA diet, as compared to those fed the SFA diet (p < 0.001). The SFA diet reduced IRS-1 expression and phosphorylated PI3K levels in skeletal muscle, as compared with a chow
diet (p < 0.001, respectively). On the contrary, muscle IRS-2 expression and phosphorylated ERK1/2 was significantly increased in
rats fed the SFA diet (p < 0.001, respectively). Membrane translocation of glucose transporter type 4 decreased in the skeletal muscle of rats fed
the SFA diet, as compared to those fed a chow diet (p < 0.001). These changes in insulin signaling pathway in skeletal muscle were not observed in rats fed the MUFA diet. In conclusion,
the beneficial effect of dietary MUFA on insulin sensitivity is associated with a conserved IRS-1/PI3K insulin signaling pathway
which was altered by dietary SFA. 相似文献
6.
I. Steiner J. Washüttl G. Kroyer F. Streichsbier 《European Journal of Lipid Science and Technology》1983,85(7):280-282
Chemical Investigations of Ozonized Safflor Oil To continue the investigations of ozonized olive oil ozonized safflor oil was analysed with respect to some parameters which are important for medical application: peroxide value, malondialdehyd content, total fatty acids, fatty acids in the triglyceride fraction with and without peroxide groups in ozonized safflor oil. The high peroxide value and the increased amount of malondialdehyd with respect to ozonized olive oil was striking. Furthermore the high content of myristic acid in the oil or of linoleic acid in the triglyceride fraction, containing peroxide groups (content in safflor oil 36%) and lauric, myristic and oleic acid in the triglyceride fraction without peroxide groups. 相似文献
7.
Amy E Griel Penny M Kris-Etherton Kirsten F Hilpert Guixiang Zhao Sheila G West Rebecca L Corwin 《Nutrition journal》2007,6(1):2
Human, animal, and in vitro research indicates a beneficial effect of appropriate amounts of omega-3 (n-3) polyunsaturated
fatty acids (PUFA) on bone health. This is the first controlled feeding study in humans to evaluate the effect of dietary
plant-derived n-3 PUFA on bone turnover, assessed by serum concentrations of N-telopeptides (NTx) and bone-specific alkaline
phosphatase (BSAP). Subjects (n = 23) consumed each diet for 6 weeks in a randomized, 3-period crossover design: 1) Average
American Diet (AAD; [34% total fat, 13% saturated fatty acids (SFA), 13% monounsaturated fatty acids (MUFA), 9% PUFA (7.7%
LA, 0.8% ALA)]), 2) Linoleic Acid Diet (LA; [37% total fat, 9% SFA, 12% MUFA, 16% PUFA (12.6% LA, 3.6% ALA)]), and 3) α-Linolenic
Acid Diet (ALA; [38% total fat, 8% SFA, 12% MUFA, 17% PUFA (10.5% LA, 6.5% ALA)]). Walnuts and flaxseed oil were the predominant
sources of ALA. NTx levels were significantly lower following the ALA diet (13.20 ± 1.21 nM BCE), relative to the AAD (15.59
± 1.21 nM BCE) (p < 0.05). Mean NTx level following the LA diet was 13.80 ± 1.21 nM BCE. There was no change in levels of
BSAP across the three diets. Concentrations of NTx were positively correlated with the pro-inflammatory cytokine TNFα for
all three diets. The results indicate that plant sources of dietary n-3 PUFA may have a protective effect on bone metabolism
via a decrease in bone resorption in the presence of consistent levels of bone formation. 相似文献
8.
Dietary ALA,But not LNA,Increase Growth,Reduce Inflammatory Processes,and Increase Anti‐Oxidant Capacity in the Marine Finfish Larimichthys crocea 下载免费PDF全文
Whilst aquaculture feed is increasingly formulated with the inclusion of plant oils replacing fish oil, and increasing research effort has been invested in understanding the metabolic effects of reduced dietary n‐3 long chain poly unsaturated fatty acids (n‐3 LC‐PUFA), relatively little information is available on the potential direct metabolic roles of dietary alpha‐linolenic acid (ALA, 18:3n‐3) and alpha‐linolenic acid/linoleic acid (LNA, 18:2n‐6) ratio in cultured marine finfish species. In this study, four plant oil based diets, with varying ALA/LNA ratio (0.0, 0.5, 1.0 and 1.5) were fed to juvenile large yellow croakers (Larimichthys crocea) and compared to a fish oil‐based control diet (CD) to evaluate the resulting effects on growth, nonspecific immunity, anti‐oxidant capacity and related gene expression. High dietary LNA negatively impacted fish growth performance, nonspecific immunity and antioxidant capacity, but growth and immunity were maintained to levels comparable to CD by increasing the ratio of dietary ALA/LNA. The over‐expression of genes associated with inflammation (cyclooxygenase‐2 and interleukin‐1β) and fatty acid oxidation (carnitine palmitoyl transferase I and acyl CoA oxidase) in croakers fed high concentrations of LNA were reduced to levels comparable to those fed CD by increasing dietary ALA/LNA. This study showed that dietary ALA, by increasing the overall n‐3/n‐6 PUFA ratio, exerts direct anti‐inflammatory and antioxidant effects, similar to those exerted by dietary n‐3 LC‐PUFA. 相似文献
9.
The n-6/n-3 fatty acid (FA) ratio has increased in the Western-style diet to ~10–15:1 during the last century, which may have
contributed to the rise in cardiovascular disease (CVD). Prior studies have evaluated the effects on CVD risk factors of manipulating
the levels of n-6 and n-3 FA using food and supplements or investigated the metabolic fate of linoleic acid (LNA) and α-linolenic
acid (ALA) by varying the n-6/n-3 ratios. However, no previous studies have investigated the potential interaction between
diet ratios and supplementation with eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3). We used
a factorial design approach with adults (n = 24) in a controlled feeding trial to compare the accretion of EPA and DHA into red blood cell membranes (RBC) by adding
a direct source (algal oil supplement) of EPA and DHA in a diet with a 10:1 versus 2:1 ratio of n-6/n-3 FA. Subjects were
randomized into 8-week crossover diet sequences and each subject consumed three of four diets [10:1, 10:1 plus supplement
(10:1 + S), 2:1 and 2:1 + S]. LNA and ALA intakes were 9.4 and 7.7%, and 1.0 and 3.0% during the low and high ALA diets, respectively.
Compared to the Western-style 10:1 diet, the 2:1 diet increased EPA by 60% (P < 0.0001) in RBC membranes without the direct EPA source and a 34% increase (P = 0.027) was observed with the 10:1 + S diet; however, DHA levels increased in both diet ratios only with a direct DHA source.
Shifting towards a 2:1 diet is a valid alternative to taking EPA-containing supplements. 相似文献
10.
Dietary High‐Oleic Acid Soybean Oil Dose Dependently Attenuates Egg Yolk Content of n‐3 Polyunsaturated Fatty Acids in Laying Hens Fed Supplemental Flaxseed Oil 下载免费PDF全文
Chickens can hepatically synthesize eicosapentaenoic acid (20:5 n‐3) and docosahexaenoic acid (22:6 n‐3) from α‐linolenic acid (ALA; 18:3 n‐3); however, the process is inefficient and competitively inhibited by dietary linoleic acid (LNA; 18:2 n‐6). In the present study, the influence of dietary high‐oleic acid (OLA; 18:1 n‐9) soybean oil (HOSO) on egg and tissue deposition of ALA and n‐3 polyunsaturated fatty acids (PUFA) synthesized from dietary ALA was investigated in laying hens fed a reduced‐LNA base diet supplemented with high‐ALA flaxseed oil (FLAX). We hypothesized that reducing the dietary level of LNA would promote greater hepatic conversion of ALA to very long‐chain (VLC; >20C) n‐3 PUFA, while supplemental dietary HOSO would simultaneously further enrich eggs with OLA without influencing egg n‐3 PUFA contents. Nine 51‐week‐old hens each were fed 0, 10, 20, or 40 g HOSO/kg diet for 12 weeks. Within each group, supplemental dietary FLAX was increased every 3 weeks from 0 to 10 to 20 to 40 g/kg diet. Compared to controls, dietary FLAX maximally enriched the total n‐3 and VLC n‐3 PUFA contents in egg yolk by 9.4‐fold and 2.2‐fold, respectively, while feeding hens 40 g HOSO/kg diet maximally attenuated the yolk deposition of ALA, VLC n‐3 PUFA, and total n‐3 PUFA by 37, 15, and 32%, respectively. These results suggest that dietary OLA is not neutral with regard to the overall process by which dietary ALA is absorbed, metabolized, and deposited into egg yolk, either intact or in the form of longer‐chain/more unsaturated n‐3 PUFA derivatives. 相似文献
11.
Samia Dabbou Ikbel Chaieb Imed Rjiba Manel Issaoui Adel Echbili Amel Nakbi Noureddine Gazzah Mohamed Hammami 《Journal of the American Oil Chemists' Society》2012,89(4):667-674
The fatty acid (FA) composition of 540 Tunisian virgin olive oil hybrids (VOO) were classified by principal component analysis
(PCA). Pearson correlation between FA variables revealed an inverse association between C18:1 and C18:2; C18:1 and C16:0,
while C16:0 and C16:1 were positively correlated. PCA yielded five significant PCs, which together account for 79.95% of the
total variance; with PC1 contributing 36.84% of the total. Eigenvalue analysis revealed that PC1 was mainly attributed to
C18:1, monounsaturated fatty acids (MUFA) and the ratios oleic/linoleic (O/L) and monounsaturated fatty acids/polyunsaturated
fatty acids (MUFA/PUFA); PC2, by C16:0, saturated fatty acids (SFA) and the palmitic/linoleic ratio (P/L); PC3 by C18:2 and
C22:0, PC4 by C18:0 and PC5, by C17:1. Then, PCA analysis indicated that in addition to C16:0, C18:0, C18:1, C17:1, and C22:0,
MUFA, SFA and the ratios O/L, P/L and MUFA/PUFA were determined to be the main factors responsible for the olive oil hybrids
discrimination. 相似文献
12.
The efficacy of individual ω-t-3 polyunsaturated fatty acids (PUFA) in altering eicosanoid synthesis in peritoneal macrophages
was studied by feeding mice for 10 days a diet containing 2 wt% fat, which included 0.5 wt% ethyl esters of eicosapentaenoic
acid (EPA), docosahexaenoic acid (DHA) or linolenic acid (LNA). Upon stimulation with calcium ionophore A23187, macrophages
from these animals produced significantly lower amounts of leukotriene C4, leukotriene B4 and 12-hydroxyeicosatetraenoic acid, prostaglandin E2 and 6-keto prostaglandin F1α compared with those obtained from animals on the diets containing olive oil or safflower oil. The decrease in leukotriene
synthesis was similar in the animals fed DHA, EPA or LNA diets. This depression of eicosanoids by DHA and EPA was associated
with decreased levels of arachidonic acid (AA); however, LA that altered eicosanoids did not have the same effect on AA levels. 相似文献
13.
José L. Periago María L. Pita María A. Sanchez del Castillo Guillermo Caamaño María D. Suárez 《Lipids》1989,24(5):383-388
Changes in fatty acid composition, microsomal Δ9- and Δ6-desaturase activities and liver contents of cholesterol and phospholipids were studied in rats fed medium chain triglyceride-supplemented
diets. Weanling rats were divided into four groups and fed for three weeks a basal diet with different 10%-fat supplements:
corn oil, medium chain triglyceride-corn oil, olive oil and medium chain triglyceride-olive oil. The highest relative content
of saturated fatty acids corresponded to corn oil-fed animals. Both monounsaturated fatty acid content and Δ9-desaturase activity were higher in the animals fed olive oil diets than in corn oil-fed rats. The long chain polyunsaturated
fatty acids of the n−3 series were increased in the olive oil and medium chain triglyceride-olive oil-fed groups probably
due to the lower linoleic/α-linolenic ratios found in these two diets. The cholesterol/phospholipid molar ratio was unaffected
by diet and the unsaturation index was only slightly changed in the four groups. Thus, some mechanism may be operative under
these conditions to maintain the homeostasis of the membrane. 相似文献
14.
We examined the effect of diet on gallstone incidence and the composition of biliary phosphatidylcholines in methyltestosterone-treated
female hamsters. These hamsters were fed a nutritionally adequate purified lithogenic diet containing 2% corn oil, 4% butterfat,
0.3% cholesterol, and 0.05% methyltestosterone, resulting in a cholesterol gallstone incidence of 86%. This incidence was
lowered when mono-and polyunsaturated fats or fatty acids were added to the diet: 2.5% oleic acid resulted in total prevention
of cholesterol cholelithiasis, 2.5% linoleic acid, and 4% safflower oil (78% linoleic acid content) reduced gallstone incidence
to 26 and 8%, respectively. An additional 4% butterfat (29% oleic acid content) produced gallstones in 50% of the animals.
At the end of the 6-wk feeding period, the bile of all hamsters was supersaturated with cholesterol. The major biliary phosphatidylcholine
species in all groups were (sn-1-sn-2): 16:0–18:2, 16:0–18:1, 18:0–18:2, 16:0–20:4, and 18:2–18:2. The safflower oil-and linoleic acidfed hamsters exhibited
an enrichment of 16:0–18:2 (16–18%); added butterfat or oleic acid increased the proportion of 16:0–18:1 (9 and 25%, respectively).
We conclude that the phosphatidylcholine molecular species in female hamster bile can be altered by dietary fats/fatty acids
and that mono-and polyunsaturated fatty acids play a role in suppressing the induced cholelithiasis. 相似文献
15.
Lower Efficacy in the Utilization of Dietary ALA as Compared to Preformed EPA + DHA on Long Chain n-3 PUFA Levels in Rats 总被引:1,自引:1,他引:0
Ramaprasad R. Talahalli Baskaran Vallikannan Kari Sambaiah Belur R. Lokesh 《Lipids》2010,45(9):799-808
We made a comparative analysis of the uptake, tissue deposition and conversion of dietary α-linolenic acid (ALA) to its long
chain metabolites eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) with preformed EPA + DHA. Diets containing linseed
oil [with ALA at ~2.5 (4 g/kg diet), 5 (8 g/kg diet), 10 (16 g/kg diet), 25% (40 g/kg diet)] or fish oil [with EPA + DHA at
~1 (1.65 g/kg diet), 2.5 (4.12 g/kg diet), 5% (8.25 g/kg diet)] or groundnut oil without n-3 polyunsaturated fatty acids (n-3
PUFA) were fed to rats for 60 days. ALA and EPA + DHA in serum, liver, heart and brain increased with increments in the dietary
ALA level. When preformed EPA + DHA were fed, the tissue EPA + DHA increased significantly compared to those given ALA. Normalized
values from dietary n-3 PUFA to tissue EPA + DHA indicated that 100 mg of dietary ALA lead to accumulation of EPA + DHA at
2.04, 0.70, 1.91 and 1.64% of total fatty acids respectively in liver, heart, brain and serum. Similarly 100 mg of preformed
dietary EPA + DHA resulted in 25.4, 23.8, 15.9 and 14.9% of total fatty acids in liver, heart, brain and serum respectively.
To maintain a given level of EPA + DHA, the dietary ALA required is 12.5, 33.5, 8.3 and 9.1 times higher than the dietary
EPA + DHA for liver, heart, brain and serum respectively. Hence the efficacy of precursor ALA is lower compared to preformed
EPA + DHA in elevating serum and tissue long chain n-3 PUFA levels. 相似文献
16.
Turkey hens were fed diets containing no added fat nor diets supplemented with soybean oil or neatsfoot oil. The composition
of neutral and polar lipid fatty acids present in the unincubated turkey egg yolk was compared with that of those present
in the yolk sac of the developing turkey embryo at different stages of development. Comparisons were made of the fatty acid
fractions in the entire embryo homogenates, except liver and heart, which were analyzed separately. Changes in the relative
amounts of the fatty acids are reported as affected by age of the embryo and by dietary lipids. The fatty acids from both
the neutral and polar lipids which were utilized to the greatest extent for embryonic development were palmitoleic, oleic,
linoleic, and linolenic, regardless of the dietary supplements. Arachidonic, tetracosenoic, and docosahexaenoic acids also
were metabolized by the embryo. Saturated fatty acids, used by the embryo as development progressed, were palmitic, stearic,
and arachidic acids. Analyses of the liver fatty acids showed that the C16∶0 C16∶1, C18∶0, C18∶1, and C20∶4 acids in the neutral
and polar lipids decreased with embryonic development and varied with the type of diet. The heart contained low levels of
myristic, palmitic, stearic, arachidic, and arachidonic acids in the neutral lipids and palmitoleic and oleic acids in the
polar lipids. 相似文献
17.
Beef tallow and cottonseed oil were mixed with a pure butterfat in the ratios of 2%, 4% and 6% to obtain admixtures of beef
tallow with butterfat and cottonseed oil with butterfat. The hydrolysis of individual triglycerides was carried out using
the lipase to obtain 2-monoglycerides. The results indicated that butterfat had a higher percentage of C14:0 and C16:0 acids
than found in the triglycerides and 2-monoglycerides of beef tallow and cottonseed oil.
Beef tallow contained a higher proportion of C18:0 and C18:1 acids than butterfat and cottonseed oil triglycerides or 2-monoglycerides.
Cottonseed oil had a higher percentage of C18:2 acid located in triglyceride or 2-monoglyceride than found in butterfat or
beef tallow triglycerides and 2-monoglycerides.
The analysis of the samples of butterfat containing 2%, 4% and 6% beef tallow revealed that the addition of beef tallow to
butterfat affected the fatty acid composition of butterfat triglycerides and 2-monoglycerides with C18:0 and C18:1 acids;
the effect was increased with increasing percentages of beef tallow.
The addition of cottonseed oil to butterfat in the ratios of 2%, 4% and 6% affected the fatty acid composition of butterfat
triglycerides and 2-monoglycerides. It was found that both C18:1 and C18:2 increased as the added cottonseed oil percentages
increased. 相似文献
18.
In the present study, changes in phospholipid compositions of liver microsomes, erythrocyte membranes, platelets, aorta, cardiac
muscle and brain of rats fed olive oil were compared with those of rats fed sunflower oil. Four groups of rats starting at
weaning were fed for four weeks a basal diet containing 5 or 25% olive oil or sunflower oil. We found that oleic acid was
higher and linoleic acid was lower in membrane phospholipids of olive oil fed rats compared to sunflower oil fed rats. Polyunsaturated
fatty acids of the n−3 series were markedly elevated in all tissues of rats on the olive oil diets relative to those on the
sunflower oil diets. The results are consistent with a lower linoleic/linolenic acid ratio induced by the olive oil diets,
suggesting a positive correlation between olive oil ingestion and n−3 polyunsaturated fatty acid levels in cell and tissue
lipids. The study suggests that an adequate intake of olive oil may enhance the conversion of n−3 fatty acids. 相似文献
19.
Victor M. Balcão Asmo Kemppinen F. Xavier Malcata Paavo J. Kalo 《Journal of the American Oil Chemists' Society》1998,75(10):1347-1358
Butterfat was chemically modified via combined hydrolysis and interesterification, catalyzed by a commercial lipase immobilized onto a bundle of hydrophobic hollow
fibers. The main goal of this research effort was to engineer butterfat with improved nutritional properties by taking advantage
of the sn-1,3 specificity and fatty acid specificity of a lipase in hydrolysis and ester interchange reactions, and concomitantly decrease
its level of long-chain saturated fatty acid residues (viz., lauric, myristic, and palmitic acids) and change its melting properties. All reactions were carried out at 40°C in a solvent-free
system under controlled water activity, and their extent was monitored via chromatographic assays for free fatty acids, esterified fatty acid moieties, and triacylglycerols; the thermal behavior of
the modified butterfat was also assessed via calorimetry. Lipase-modified butterfat possesses a wider melting temperature range than regular butterfat. The total saturated
triacylglycerols decreased by 2.2%, whereas triacylglycerols with 28–46 acyl carbons (which contained two or three lauric,
myristic, or palmitic acid moieties) decreased by 13%. The total monoene triacylglycerols increased by 5.4%, whereas polyene
triacylglycerols decreased by 2.9%. The triacylglycerols of interesterified butterfat had ca. 10.9% less lauric, 10.7% less myristic, and 13.6% less palmitic acid residues than those of the original butterfat. 相似文献
20.
This study was designed to examine the effects of dietary n−3 and n−6 polyunsaturated fatty acids (PUFA) on postprandial lipid
levels and fatty acid composition of hepatic membranes. Male Sprague-Dawley rats were trained for a 3−h feeding protocol and
fed one of five semipurified diets: one fat-free diet or one of four diets supplemented with 10% (by weight) each of corn
oil, beef tallow, perilla oil, and fish oil. Two separate experiments were performed, 4-wk long-term and 4-d short-term feeding
models, to compare the effects of feeding periods. Postprandial plasma lipid was affected by dietary fats. Triacylglycerol
(TG) and total cholesterol levels were decreased in rats fed perilla oil and fish oil diets compared with corn oil and beef
tallow diets. Hepatic TG and total cholesterol levels were also reduced by fish oil and perilla oil diets. Fatty acid composition
of hepatic microsomal fraction reflected dietary fatty acids and their metabolic conversion. The major fatty acids of rats
fed the beef tallow diet were palmitic, stearic, and oleic. Similarly, linoleic acid (LA) and arachidonic acid in the corn
oil group, α-linolenic acid (ALA) and eicosapentaenoic acid (EPA) in the perilla oil group, and palmitic acid and docosahexaenoic
acid (DHA) in the fish oil group were detected in high proportions. Both long- and short-term feeding experiments showed similar
results. In addition, microsomal DHA content was negatively correlated with plasma lipid levels. Hepatic lipid levels were
also negatively correlated with EPA and DHA contents. These results suggest that n−3 ALA has more of a hypolipidemic effect
than n−6 LA and that the hypolipidemic effect of n−3 PUFA may be partly related to the increase of EPA and DHA in hepatic
membrane. 相似文献