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1.
Bile salt lipid emulsions were prepared which simulated the emulsified oil-micellar phase system of the small intestinal content
during fat digestion.
Application of such emulsions to gel columns prepared and eluted with 6 mM sodium taurodeoxycholate separated an emulsion
phase and a micellar phase. The distribution of lipid solutes into the two phases under these conditions was measured.
Micellar dimensions were larger as lipid concentrations were increased. Inclusion of multiple lipid classes resulted in larger
micellar particles.
Monoglyceride and fatty acids were eluted completely in the micellar phase under these conditions. Minimal measurable amounts
of triolein were recovered in micellar solution. This was confirmed by extraction, chromatographic separation and quantitative
analysis. As diolein concentration was increased, less was recovered in the micellar phase. When monoglyceride was added,
more diolein entered the micellar phase. Addition of triglyceride enhanced the distribution of diolein into the emulsion phase. 相似文献
2.
Renée Grataroli Monique Charbonnier Gilles Nalbone Denis Lairon Christiane Chabert Jacques C. Hauton Huguette Lafont 《Lipids》1985,20(11):765-772
Intralipid was incubated with pancreatic lipase (EC 3.1.1.3) and/or phospholipase A2 (EC 3.1.1.4) at two bile salts/phosphatidylcholine molar ratios and at two different triglyceride hydrolysis rates using
various amounts of lipase.
Incubations were studied by gel filtration. Results show: (i) During lipase action, three phases of lipids coexist: an emulsified
phase, a micellar phase and an intermediate heavy phase sized between the two others. The equilibrium between each phase is
dependent upon the bile salts concentration. (ii) Under these conditions, pancreatic lipase was at 60% bound to the emulsified
phase, whereas pancreatic phospholipase A2 was bound at 94% to the micellar phase. 相似文献
3.
Comparative effects of feeding dietary linoleic (safflower oil) and α-linolenic (linseed oil) acids on the cholesterol content
and fatty acid composition of plasma, liver, heart and epididymal fat pads of rats were examined. Animals fed hydrogenated
beef tallow were used as isocaloric controls. Plasma cholesterol concentration was lower and the cholesterol level in liver
increased in animals fed the safflower oil diet. Feeding the linseed oil diet was more effective in lowering plasma cholesterol
content and did not result in cholesterol accumulation in the liver. The cholesterol concentration in heart and the epididymal
fat pad was not affected by the type of dietary fatty acid fed. Arachidonic acid content of plasma lipids was significantly
elevated in animals fed the safflower oil diet and remained unchanged by feeding the linseed oil diet, when compared with
the isocaloric control animals fed hydrogenated beef tallow. Arachidonic acid content of liver and heart lipids was lower
in animals fed diets containing safflower oil or linseed oil. Replacement of 50% of the safflower oil in the diet with linseed
oil increased α-linolenic, docosapentaenoic and docosahexaenoic acids in plasma, liver, heart and epididymal fat pad lipids.
These results suggest that dietary 18∶2ω6 shifts cholesterol from plasma to liver pools followed by redistribution of 20∶4ω6
from tissue to plasma pools. This redistribution pattern was not apparent when 18∶3ω3 was included in the diet. 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.
Edgar Uquiche Ximena Fica Katherine Salazar José M. del Valle 《Journal of the American Oil Chemists' Society》2012,89(6):1135-1144
This work explored the possibility of using supercritical carbon dioxide (SC-CO2) to achieve fractionation of pre-pressed rapeseed (Brassica napus) cake oil at 30–50 MPa, at 40 or 80 °C, and increase the concentration of minor lipids (sterols, tocopherols, carotenoids) in the oil. Minor lipids are partially responsible for desirable antioxidant effects that protect against degradation and impart functional value to the oil. The weight and concentration of minor lipids in oil fractions collected during the first 60 min were analyzed. Cumulative oil yield increased with pressure, and with temperature at ≥40 MPa, but was lower at 80 °C than at 40 °C when working at pressure ≤35 MPa. Differences in solubility between the oil and minor lipids explained fractionation effects that were small for tocopherols. Unlike tocopherols, which are more soluble in SC-CO2 than the oil, sterols and carotenoids are less soluble than the oil, and their concentration increased in the later stages of extraction, particularly at ≥40 MPa, when there was not enough oil to saturate the CO2 phase. Because of the fractionating effects on rapeseed oil composition, there was an increase in the antioxidant activity of the oil in the second half as compared to the first half of the extraction. Consequently, this study suggests that SC-CO2 extraction could be used to isolate vegetable oil fractions with increased functional value. 相似文献
6.
This study examined the effect on the plasma lipids and plasma phospholipid and cholesteryl ester fatty acids of changing
from a typical western diet to a very low fat (VLF) vegetarian diet containing one egg/day. The effect of the addition of
saturated, monounsaturated or polyunsaturated fat (PUFA) to the VLF diet was also examined. Three groups of 10 subjects (6
women, 4 men) were fed the VLF diet (10% energy as fat) for two weeks, and then in the next two weeks the dietary fat in each
group was increased by 10% energy/week using butter, olive oil or safflower oil. The fat replaced dietary carbohydrate. The
VLF diet reduced both the low density lipoprotein (LDL)-and high density lipoprotein (HDL)-cholesterol levels; addition of
the monounsaturated fats and PUFA increased the HDL-cholesterol levels, whereas butter increased the cholesterol levels in
both the LDL- and HDL-fractions. The VLF diet led to significant reductions in the proportion of linoleic acid (18∶2ω6) and
eicosapentaenoic acid (20∶5ω3) and to increases in palmitoleic (16∶1), eicosatrienoic (20∶3ω6) and arachidonic acids (20∶4ω6)
in both phospholipids and cholesteryl esters. Addition of butter reversed the changes seen on the VLF diet, with the exception
of 16∶1, which remained elevated. Addition of olive oil resulted in a significant rise in the proportion of 18∶1 and significant
decreases in all ω3 PUFA except 22∶6 compared with the usual diet. The addition of safflower oil resulted in significant increases
in 18∶2 and 20∶4ω6 and significant decreases in 18∶1, 20∶5ω3 and 22∶5ω3. These results indicate that the reduction of saturated
fat content of the diet (<6% dietary energy), either by reducing the total fat content of the diet or by exchanging saturated
fat with unsaturated fat, reduced the total plasma cholesterol levels by approximately 12% in normocholesterolemic subjects.
Although the VLF vegetarian diet reduced both LDL- and HDL-cholesterol levels, the long-term effects of VLF diets are unlikely
to be deteterious since populations which habitually consume these diets have low rates of coronary heart disease. The addition
of safflower oil or olive oil to a VLF diet produced favorable changes in the lipoprotein lipid profile compared with the
addition of butter. The VLF diets and diets rich in butter, olive oil or safflower oil had different effects on the 20 carbon
eicosanoid precursor fatty acids in the plasma. This suggests that advice on plasma lipid lowering should also take into account
the effect of the diet on the fatty acid profile of the plasma lipids. 相似文献
7.
As complex lipid systems, the phase and crystallization behavior of mixtures of a high-melting milk fat fraction with a low-melting
milk fat fraction or canola oil was studied. A turbidity technique was developed to estimate solubility and metastability
conditions of these lipid mixtures. Both solubility and metastability of the high-melting milk fat fraction in liquid lipids
increased exponentially with temperature. At a given equilibration temperature, liquid phases and solid fractions with nearly
identical melting profiles and TAG compositions were obtained regardless of the original concentration of the lipid mixture.
The maximum melting temperature (MMT), as measured by DSC, of the liquid phase increased dramatically in the equilibrium temperature
range of 27.5–35.0°C but did not change at temperatures below and above this range (down to 25.0°C and up to 40°C in this
study). The content of long-chain TAG (C46−C52) increased and short-chain TAG (C36−C40) decreased in the liquid phases as the equilibrium temperature increased. A plot of the TAG group ratio (i.e, long-short-chain
TAG) vs. equilibrium temperature was generated to illustrate the phase behavior of the complex lipid system and to represent
a solubility curve, from which the supersaturation level for crystallization kinetics was determined. Higher supersaturation
and lower temperature resulted in higher nucleation and crystallization rates. Compared to the system with a low-melting milk
fat fraction, mixtures of the high-melting milk fat fraction with canola oil had higher nucleation and crystallization rates
due to the lower solubility found for this system. 相似文献
8.
Effect of long and medium chain length lipids upon aqueous solubility of α-tocopherol 总被引:1,自引:0,他引:1
The efficiency by which α-tocopherol is solubilized in vitro into mixed bile salt micelles containing different lipids was studied. Alterations in solubility due to addition to the incubation media of triglyceride, free fatty acid, monoglyceride, and lecithin of either long or medium chain length were examined. Results are expressed as a partition ratio between a micellar and an oil phase. The triglyceride of both long and medium chain length fatty acids greatly decreased the solubility of α-tocopherol in bile salt solutions. When added singly, monoglyceride and lecithin of long chain length fatty acids increased the α-tocopherol solubilized four- to fivefold; fatty acids of either chain length and medium chain monoglyceride when added singly had no significant effect upon the tocopherol solubilized. An additive effect was observed when a combination of long chain monoglyceride and lecithin was added. Addition of fatty acid to this combination, however, significantly decreased the α-tocopherol solubility into the micellar phase. Although the solubility of α-tocopherol was increased by all combinations of medium chain length polar lipids, except the fatty acid-monoglyceride pair, the effect was three to seven times less than for the corresponding long chain mixture. 相似文献
9.
Dorota Johansson Björn Bergenståhl Eva Lundgren 《Journal of the American Oil Chemists' Society》1995,72(8):921-931
Wetting of fat crystals has been extensively examined in this work by contact angle (θ) measurements of fat crystal, oil,
and water in three-phase contact. Contact angle was measured in oil. The crystals were nonpolar and wetted by oil for a contact
angle equal to 0°, and polar and wetted by water for an angle equal to 180°. Fat crystals are expected to contribute to the
stability of margarine emulsions if they are preferentially wetted by the oil phase (0°<θ<90°), but result in instability
if they are preferentially wetted by the water phase (90°<θ<180°). In the absence of oil and water additives, fat crystals
in α and β' polymorphs were introduced to the oil/water interface from the oil side (contact angle θ ∼ 30°). β Polymorphs
were completely wetted by oil (θ ≈ 0°). The contact angle for β' crystals decreased with increasing temperature and was slightly
lower in butter oil than in soybean oil. Emulsifiers in the oil phase (lecithins, monoglycerides and their esters, ethoxylated
emulsifiers) and surface-active proteins in the water phase (milk proteins) made the crystals more polar (higher θ). Nonsurface-active
proteins, sugar, and citric acid had no significant effect, although concentrations of salt lowered θ. Contact angle increased
with temperature for emulsifiers of limited solubility in the oil, e.g., saturated monoglyceride. 相似文献
10.
Annett Knoth Inta Scherze Gerald Muschiolik 《European Journal of Lipid Science and Technology》2005,107(12):857-863
Water‐in‐oil (W/O, 30:70) emulsions were prepared with phosphatidylcholine‐depleted lecithin [PC/(PI,PE) = 0.16] or polyglycerol polyricinoleate (PGPR) as emulsifying agents by means of pressure homogenization. The effect of lipid type (medium‐chain triacylglycerols, sunflower, olive, butter oil, or MCT‐oil/vegetable fat blends) was investigated in relation to particle size distribution, coalescence stability and the sedimentation of the water droplets. A significant correlation (p <0.05) was observed between the interfacial pressure caused by the addition of lecithin to the pure lipids and the specific surface area of the emulsion droplets (rs = 0.700), and between the viscosity of the lipids used as the continuous phase (reflecting the fatty acid composition) and the specific surface area of the emulsion droplets (rs = 0.8459) on the other hand. Blends of vegetable fat and MCT‐oil led to reduced coalescence stability due to the attachment of fat crystals to the emulsion droplets. Lecithin‐stabilized W/O emulsions showed significantly higher viscosities compared to those stabilized with PGPR. It was possible to adjust the rheological properties of lecithin‐stabilized emulsions by varying the lipid phase. 相似文献
11.
Supplementation with conjugated linoleic acid (CLA) induces a number of physiological effects in experimental animals, including
reduced body fat content, decreased aortic lipid deposition, and improved serum lipid profile. Controlled trials on the effects
of CLA in humans have hitherto been scarce. The aim of this study was to evaluate the effects of supplementation with CLA
in healthy humans on anthropometric and metabolic variables and on the fatty acid composition of serum lipids and thrombocytes.
Fifty-three healthy men and women, aged 23–63 yr, were randomly assigned to supplementation with CLA (4.2 g/d) or the same
amount of olive oil during 12 wk in a double-blind fashion. The proportion of body fat decreased (−3.8%, P<0.001) in the CLA-treated group, with a significant difference from the control group (P=0.050). Body weight, body mass index, and sagittal abdominal diameter were unchanged. There were no major differences between
the groups in serum lipoproteins, nonesterified fatty acids, plasma insulin, blood glucose, or plasminogen activator inhibitor
1 (PAI-1). In the CLA group the proportions of stearic, docosatetraenoic, and docosapentaenoic acids increased in serum lipids
and thrombocytes, while proportions of palmitic, oleic, and dihomoγ-linolenic acids decreased, causing a decrease of the estimated
Δ-6 and Δ-9 and an increase in the Δ-5 desaturase activities. These results suggest that supplementation with CLA may reduce
the proportion of body fat in humans and that CLA affects fatty acid metabolism. No effects on body weight, serum lipids,
glucose metabolism, or PAI-1 were seen. 相似文献
12.
In previous studies, zinc-deficient rats force-fed a diet with coconut oil as the major dietary fat developed a fatty liver,
whereas zinc-deficient rats force-fed a diet with linseed oil did not. The present study was conducted to elucidate the reason
for this phenomenon. In a bifactorial experiment, rats were fed zinc-adequate or zinc-deficient diets containing either a
mixture of coconut oil (70 g/kg) and safflower oil (10 g/kg) (“coconut oil diet”) or linseed oil (80 g/kg) (“linseed oil diet”)
as a source of dietary fat, and activities of lipogenic and glycolytic enzymes in liver were determined. In order to ensure
adequate food intake, all the rats were force-fed. Zinc-deficient rats on the coconut oil diet developed a fatty liver, characterized
by elevated levels of triglycerides with saturated and monounsaturated fatty acids. These rats also had markedly elevated
activities of the lipogenic enzymes acetyl-CoA carboxylase, fatty acid synthase (FAS), glucose-6-phosphate dehydrogenase (G6PDH),
6-phosphogluconate dehydrogenase (6PGDH), and citrate cleavage enzyme, whereas activities of malic enzyme and glycolytic enzymes
were not different compared with zinc-adequate rats on the coconut oil diet. In contrast, rats receiving the linseed oil diet
had similar triglyceride concentrations regardless of zinc status, and activities of lipogenic enzymes and glycolytic enzymes
were not different between the two groups. Zinc-deficient rats fed either type of dietary fat exhibited statistically significant
correlations between activities of FAS, G6PDH, 6PGDH and concentrations of saturated and monounsaturated fatty acids in liver.
The concentrations of serum lipids were elevated in zinc-deficient rats fed either type of dietary fat. These results demonstrate
that fatty liver in zinc-deficient rats on the coconut oil diet is caused by elevated activities of lipogenic enzymes, and
not by disturbed lipid secretion from liver. Dietary linseed oil prevents both the elevation of lipogenic enzyme activity
and fatty liver in zinc-deficient rats. 相似文献
13.
A Couette-type torsion wire surface shear viscometer was used to measure the apparent interfacial shear viscosity of pH 7
(I=0.05 M) buffered solutions of sodium caseinate in contact with sunflower oil. The sunflower oil contained 1% fat crystals
in either the β or β′ polymorphic form, or was crystal free. In all cases, the fat crystals increased the interfacial shear
viscosity synergistically, with the β′ crystals causing the biggest increase. Substituting the protein for a small-molecule
surfactant (Tween-40) showed that this was not simply due to the protein lowering the interfacial tension. Sedimentation studies
of the different fat crystal slurries suggested that the extent of the interfacial shear viscosity increase was related to
the strength of crystal-crystal interactions in the oil phase. It seems likely that when protein is present at the interface,
it fixes the adsorbed layer of fat crystals to the cross-linked protein film at the interface. When this film was sheared,
the strength of the crystal-crystal interactions in the oil phase became important. However, when Tween-40 was in the aqueous
phase instead of the protein, the crystal-crystal interactions were not relevant, presumably because the Tween-40 interfacial
film simply flowed around the adsorbed crystals 相似文献
14.
Semipurified diets containing different lipids were fed to rat dams during lactation and subsequently to their pups for 33
weeks post-weaning. Some rats within each group were exposed to oxygen at hyperbaric pressure (OHP). Lipid peroxide levels
were lower in lungs of rats fed 7% hydrogenated coconut oil or 10% butter as compared with their controls, fed 7% corn oil
or 10% safflower oil, respectively. Exposure to OHP increased lung peroxide levels. This increase varied with the type of
fat in the diet. Studies of the fatty acid composition indicate that lipid peroxide levels generally increased with an increase
in the levels of 18∶2 in lung total lipids. The results suggest that the type of dietary lipid may alter the susceptibility
of the animal to pulmonary oxygen toxicity. 相似文献
15.
Dorota Johansson Björn Bergenståhl 《Journal of the American Oil Chemists' Society》1995,72(8):911-920
Several foods contain semi-solid fats that consist of solid crystals dispersed in a liquid oil. In oil-continuous margarine,
butter, and chocolate, fat crystals determine properties such as consistency, stability against oiling-out, and emulsion stability.
Trends toward foods with less fat and/or less saturated fat create a need for understanding and controlling the properties
of fat crystal dispersions. Fat crystals form a network in oil due to mutual adhesion. One source of strong adhesion is formation
of solid bridges (sintering), which has been studied in this work through sedimentation and rheological experiments. Results
indicate that sintering may be created by crystallization of a fat phase with a melting point between that of the oil and
the crystal. Generally speaking, β′ crystals were sintered by β′ fat bridges, favored by rapid cooling, and β crystals by
β fat bridges, favored by slow cooling. The existence of the same polymorphic form of the crystal and bridge indicated that
solid bridges, rather than bridges formed by small crystal nuclei, were formed. A maximum in sintering ability for an optimal
sintering fat concentration occurred due to competition between bridge formation and other crystallization processes. Some
emulsifiers influenced the sintering process. For example, monooolein made it more pronounced, while technical lecithin had
the opposite effect. 相似文献
16.
Rats were fed diets high in either saturated fat (beef tallow) or α-linolenic acid (linseed oil) or eicosapentaenoic and docosahexaenoic
acids (fish oil) with or without 2% cholesterol supplementation. Consumption of linseed oil and fish oil diets for 28 days
lowered arachidonic acid content of plasma, liver and heart phospholipids. Addition of 2% cholesterol to diets containing
beef tallow or linseed oil lowered 20∶4ω6 levels but failed to reduce 20∶4ω6 levels when fed in combination with fish oil.
Feeding ω3 fatty acids lowered plasma cholesterol levels. Addition of 2% cholesterol to the beef tallow or linseed oil diet
increased plasma cholesterol concentrations but not when fish oil was fed. Feeding the fish oil diet reduced the cholesterol
content of liver, whereas feeding the linseed oil diet did not. Dietary cholesterol supplementation elevated the cholesterol
concentration in liver in the order: linseed oil > beef tallow > fish oil (8.6-, 5.5-, 2.6-fold, respectively). Feeding fish
oil and cholesterol apparently reduced 20∶4ω6 levels in plasma and tissue lipids. Fish oil accentuates the 20∶4ω6 lowering
effect of dietary cholesterol and appears to prevent accumulation of cholesterol in plasma and tissue lipids under a high
dietary load of cholesterol. 相似文献
17.
M
J Hossain T Takeyama Y Hayashi T Kawanishi N Shimizu R Nakamura 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1999,74(5):423-428
To enhance the Chromobacterium viscosum lipase (glycerol‐ester hydrolase; EC 3.1.1.3) activity for the reaction of water‐insoluble substrates, the AOT/isooctane reverse micellar interface was modified by co‐adsorption of a non‐ionic surfactant. Polyoxyethylene sorbitan trioleate (Tween 85) was used as the non‐ionic surfactant and olive oil as a water‐insoluble substrate. An appreciable increase of lipase activity was observed and at higher Wo values (where Wo = molar ratio of water to total surfactants of the micellar system) there was no sharp fall of the enzyme activity such as a typical bell‐shaped profile. The kinetic model for the lipase‐catalysed hydrolysis of olive oil in AOT/isooctane reverse micellar system was applied to the enzymatic reaction in this mixed reverse micellar system. It was found that the predictions of the model agree well with the experimental kinetic results and that the adsorption equilibrium constant of olive oil molecules between the micellar phase and the bulk phase of the organic solvent is smaller in AOT/Tween 85 mixed reverse micellar systems than in simple AOT reverse micellar systems. © 1999 Society of Chemical Industry 相似文献
18.
Thoracic lymph was collected from 13 dogs fed corn oil and butterfat. The chylomicrons were isolated by centrifugation. The
lipid composition of the fat core and the membrane of the chylomicron was compared to that of the surrounding lymph serum.
The fat cores contained 90–96% triglyceride, 0.7–1.9% free cholesterol, 0.2–0.5% steryl ester, 0.9–3.5% free fatty acid and
1.4–6.1% diglyceride, but no phospholipid. The lipids of the membranes contained 58–75% phospholipid, 20–35% triglyceride,
2–5% free cholesterol, 1–2% free fatty acid, and 2–3% diglyceride, but little or no steryl ester. The membrane phospholipids
were made up of 70–90% lecithin, 5–20% phosphatidyl ethanolamine, and 1–3% each of lysolecithin and sphingomyelin. The lymph
serum contained 24–47% of total lipid as phospholipid, of which 70–92% was lecithin; the phosphatidyl ethanolamine, lysolecithin
and sphingomyelin also present contributed 1–10% each. The neutral lipids of the lymph serum contained 49–75% triglyceride,
2–15% free cholesterol, 6–23% esterified cholesterol, 10–33% free fatty acid and 1–6% diglyceride.
Alterations in dietary fat, or plant sterol supplementation led to lesser changes in the lipids of the chylomicron membranes
than in the lipids of any other lymph fraction. The least variation was seen in the phospholipids.
Taken in part from a PhD Thesis submitted by T. C. Huang to Queen's University, Kingston, Canada, in April 1965. Presented
at the AOCS 56th Spring Meeting, Houston, May 1965. 相似文献
19.
trans Isometric fatty acids of partially hydrogenated fish oil (PHFO) consist oftrans 20∶1 andtrans 22∶1 in addition to thetrans isomers of 18∶1, which are abundant in hydrogenated vegetable oils, such as in partially hydrogenated soybean oil (PHSBO).
The effects of dietarytrans fatty acids in PHFO and PHSBO on the fatty acid composition of milk were studied at 0 (colostrum) and 21 dayspostpartum in sows. The dietary fats were PHFO (28%trans), or PHSBO (36%trans) and lard. Sunflower seed oil (4%) was added to each diet. The fats were fed from three weeks of age throughout the lactation
period of Experiment 1. In Experiment 2 PHFO or “fully” hydrogenated fish oil (HFO) (19%trans), in comparison with coconut oil (CF) (0%trans), was fed with two levels of dietary linoleic acid, 1 and 2.7% from conception throughout the lactation period. Feedingtrans-containing fats led to secretion oftrans fatty acids in the milk lipids. Levels oftrans 18∶1 andtrans 20∶1 in milk lipids, as percentages of totalcis+trans 18∶1 andcis+trans 20∶1, respectively, were about 60% of that of the dietary fats, with no significant differences between PHFO and PHSBO. The
levels were similar for colostrum and milk. Feeding HFO gave relatively lesstrans 18∶1 andtrans 20∶1 fatty acids in milk lipids than did PHFO and PHSBO. Only low levels ofcis+trans 22∶1 were found in milk lipids. Feedingtrans-containing fat had no consistent effects on the level of polyenoic fatty acids but reduced the level of saturated fatty acids
and increased the level ofcis+trans monoenoic fatty acids. Increasing the dietary level of linoleic acid had no effect on the secretion oftrans fatty acids but increased the level of linoleic acid in milk. The overall conclusion was that the effect of dietary fats
containingtrans fatty acids on the fat content and the fatty acid composition of colostrum and milk in sows were moderate to minor. 相似文献
20.
We have been investigating the factors determining the bioavailability of carotenoids from vegetables. The previous paper
[Rich, G.T., Bailey, A.L., Faulks, R.M., Parker, M.L., Wickham, M.S.J., and Fillery-Travis, A. (2003) Solubilization of Carotenoids
from Carrot Juice and Spinach in Lipid Phases: I. Modeling the Gastric Lumen, Lipids 38, 933–945] modeled the gastric lumen and studied the solubilization pathway of carotenes and lutein from carrot juice and
homogenized spinach to oil. Using the same vegetable preparations, we have extended our investigations to solubilization pathways
potentially available in the duodenum and looked at the ease of solubilization of carotenes and lutein within simplified lipid
micellar and oil phases present within the duodenum during digestion. Micellar solubility of raw spinach carotenoids was low
and was enhanced by freezing, which involved a blanching step. The efficiency of solubilization of carotenoids in glycodeoxycholate
micelles decreased in the order luteincarrot>luteinblanched-frozen spinach>caroteneblanched-frozen spinach>carotenecarrot. Frozen spinach carotenoids were less soluble in simple micelles of taurocholate than of glycodeoxycholate. The results comparing
the solubility of the carotenoids in mixed micelles (bile salt with lecithin) with simple bile salt micelles are explained
by the relative stability of the carotenoid in the organelle compared to that in the micelle. The latter is largely determined
by the polarity of the micelle. Below their critical micelle concentration (CMC), bile salts inhibit transfer of carotenoids
from tissue to a lipid oil phase. Above their CMC, the bile salts that solubilize a carotenoid can provide an additional route
to the oil from the tissue for that carotenoid by virtue of the equilibrium between micellar phases and the interfacial pathway.
Mixed micellar phases inhibit transfer of both carotenoids from the tissue to the oil phase, thereby minimizing this futile
pathway. 相似文献