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1.
Studies on effects of dietary fatty acids as related to their position on triglycerides 总被引:9,自引:0,他引:9
This article reviews published literature on how the stereospecific structure of dietary triglycerides may affect lipid metabolism
in humans. Animal studies have shown enhanced absorption of fatty acids in the sn-2 position of dietary triglycerides. Increasing the level of the saturated fatty acid palmitic acid in the sn-2 position (e.g., by interesterification of the fat to randomize the positions of the fatty acids along the glycerol backbone)
has been shown in rabbits to increase the atherogenic potential of the fat without impacting levels of blood lipids and lipoproteins.
In contrast, enhancing the level of stearic acid in the sn-2 position has not been found to affect either atherogenic potential or levels of blood lipids and lipoproteins in rabbit.
Fatty acids other than palmitic and stearic have not been studied systematically with respect to possible positional effects.
A limited number of human studies have shown no significant effects of interesterified fats on blood lipid parameters. However,
it is unknown whether modifying the stereospecific structure of dietary triglycerides would affect atherogenicity or other
long-term health conditions in humans. It is possible that incorporation of palmitic acid into the sn-2 position of milk fat is beneficial to the human infant (as a source of energy for growth and development) but not to human
adults. Additional research is needed to determine whether processes like interesterification, which can be used to alter
physical parameters of dietary fats (e.g., melting characteristics), may result in favorable or unfavorable long-term effects
in humans. 相似文献
2.
Klaus Eder Huldreich Nonn Holger Kluge 《European Journal of Lipid Science and Technology》2001,103(10):668-676
High concentrations of polyunsaturated fatty acids (PUFA) in meat have detrimental effects on its technical properties. The present study was carried out to investigate whether PUFA levels in pork can be reduced by increasing the concentrations of oleic acid in pig diets. To this end a bifactorial experiment was carried out with 48 female growing finishing pigs. Six different diets were used with two different concentrations of linoleic acid (12 vs. 24 g/kg) and three different concentrations of oleic acid (12 vs. 18 vs. 24 g/kg). The experiment started at a body weight (BW) of 58 kg and continued until 115 kg BW. The fatty acid composition of total lipids of backfat, perirenal fat and musculus (m.) longissimus dorsi was analysed. Concentrations of linoleic acid and total PUFA in backfat and perirenal fat were affected only by the dietary linoleic acid content but not at all by the dietary oleic acid content. Increasing the dietary concentration of oleic acid raised the level of oleic acid in those tissues at the expense of saturated fatty acids, suggesting competition between monounsaturated fatty acids and saturated fatty acids for incorporation into triglycerides. At the low dietary linoleic acid concentration, the percentages of linoleic acid and total PUFA in total lipids of m. longissimus dorsi were also unaffected by the dietary oleic acid content. In contrast, at the high dietary linoleic acid concentration, percentages of linoleic acid and total PUFA of the m. longissimus dorsi were reduced by increasing the dietary concentration of oleic acid, suggesting that oleic acid and linoleic acid compete for incorporation into muscle lipids. Thus, at high dietary linoleic acid levels the fatty acid composition of the m. longissimus dorsi was favourably affected by high dietary oleic acid concentrations; in backfat and perirenal fat, however, no beneficial effect of high dietary oleic acid levels was seen. 相似文献
3.
W. Hartfiel 《European Journal of Lipid Science and Technology》1975,77(10):417-420
Animal Fats in Animal Nutrition Intensive feeding of several types of farm animals is unthinkable without the use of fats in feed formulations. Animal fats are, however, considered inferior to plant oils with respect to quality and energy utilization. In the practical application, only mixed fat formulations are used. Therefore, there is little chance that the absorption of fat from the gastro-intestinal tract is inhibited by the presence of relatively high proportions of saturated C16 and C18 fatty acids. Large proportions of fat are used in feeds for broilers and calves. Moreover, from nutritional viewpoint, the fat content of feeds for swine and laying hen could be increased, if technical devices for restricted feeding are used, which prevent excessive intake of energy. A higher content of fat in ruminant feed is also to be recommended. Since in monogastric animals the consistency of fatty tissues is influenced by unsaturated fatty acids of dietary fat, the use of animal fats having low content of unsaturated fatty acids is favorable for the quality of slaughtered products. 相似文献
4.
Doris Oberkobusch 《European Journal of Lipid Science and Technology》1990,92(10):397-400
Polymers from Fat Derivatives by Polymer-Analogous Reaction Polymer-analogous reactions offer a synthetic route to comb-like polymers with long-chain pendant groups. In this type of reaction polymers carrying functional groups (e. g. polyacrylic acid and its esters, copolymers of maleic anhydride) are reacted with fat derivatives, e. g. fatty acids, amines, alcohols or their ethoxylates. By varying the type of polymer and fat reactant, the ratio of both or by adding further low molecular weight reactants a large variety of solid or liquid, hydrophobic or hydrophilic fat modified polymers are available. They can be used e. g. as additives in crude and motor oils or as polymer surfactants. 相似文献
5.
CLA has a range of biological properties, including effects on lipid metabolism and body composition in experimental animals.
The prevalent isomer of CLA found in the human diet is 9c, 11t-CLA, and it is predominantly found in products containing fat from ruminant animals. This study investigated the effect of
dietary CLA on energy balance in mice. Synthetic CLA reduced body fat in growing male BAI B/c mice in a dose-dependent manner
over the range 0.25–1.0% w/w CLA in the diet. Weight gain was also reduced at the highest levels of dietary CLA, being only
5.88±2.68 g/4 mice (mean±1 SD) after 4 wk of 2.0% CLA in the diet, compared with weight groups. There was no significant effect
on weight gain if diets contained 0.5% synthetic CLA or less. These results suggest that high levels of a synthetic mixture
of CLA isomers modify energy metabolism and body composition and that high levels of synthetic CLA impair weight gain and
reduce body fat pad mass in growing mice. 相似文献
6.
A. Pfalzgraf H. Steinhart M. Kuhn G. Burgstaller 《European Journal of Lipid Science and Technology》1995,97(4):159-163
48 pigs were divided into four groups and fed for different periods diets at dietary energy levels of either 11.5 MJ metabolizable energy (ME)/kg or 13 MJ ME/kg. The dietary energy restriction resulted in lower α-tocopherol contents of the musculus longissimus dorsi (m.l.d.) tissue. The aldehyde contents did not differ significantly between tissues from various feeding groups. The total aldehyde amounts ranged widely between 35 and 790 μg/kg. Correlation coefficients between these amounts and other variables of meat quality such as vitamin E, fat content, phospholipid-polyunsaturated fatty acids or conductivity, showed different relations in the various feeding groups. The aldehyde levels in tissues of the energy restricted groups were influenced by individual vitamin E, fat contents and the phospholipid composition. The aldehyde levels in tissues of animals fed the non restricted diets were independent of these lipid peroxidation stability affecting values. The correlation to the conductivity of the tissue 24 h post mortem reflected the dominating effect of physical membranal stress and stability during slaughter on the aldehyde levels. 相似文献
7.
Rats were fed (for 2 or 6 wk) purified diets containing lard (LD) or menhaden oil (MO) at two levels of dietary fat,i.e., at 11.5 and 20.8% of energy in the low fat (LF) and the medium fat (MF) diets, respectively. Following the diet period,
rats were sacrificed after either an overnight fast or after uninterruptedad libitum feeding. The studies were designed to investigate the dependence of our previously reported effects of MO,i.e. the reduction of plasma free fatty acid (FFA) levels and accumulation of hepatic triacylglycerols, on the dietary fat concentration
and the nutritional state of the animal at the time of sacrifice. Reductions in plasma triacylglycerol and cholesterol levels
in MO-fed relative to LD-fed rats were observed under all conditions. FFA levels were consistently reduced by MO-feeding at
both dietary fat concentrations, but only when blood was sampled fromad libitum fed rats. Under these conditions there was a significant positive relationship between plasma FFA and triacylglycerol concentrations.
Reduction in plasma FFA levels may be an additional mechanism associated with the triacylglycerol-lowering effect of fish
oil (FO). The LF and MF MO diets caused a rise in plasma glucose levels with no significant change in insulin concentration,
indicating that the reduction of FFA by MO was not related to changes in insulin concentration or insulin sensitivity. The
MO diets had no effect on skeletal muscle or epididymal adipose tissue lipoprotein lipase activity, demonstrating that catabolism
of triacylglycerol-rich lipoproteins contributes little, if any, to the MO-dependent reductions of plasma triacylglycerol
and FFA. The previously reported accumulation of hepatic triacylglycerols after high fat (HF; 30% of energy) MO-feeding was
not observed with the LF or MF MO diets, suggesting that the apparent direct inhibition of triacylglycerol secretion by FO
imposes a rate-limitation only when feeding HF diets. 相似文献
8.
John C Kostyak Penny Kris-Etherton Deborah Bagshaw James P DeLany Peter A Farrell 《Nutrition journal》2007,6(1):19
Background
Prepubescent children may oxidize fatty acids more readily than adults. Therefore, dietary fat needs would be higher for children compared with adults. The dietary fat recommendations are higher for children 4 to 18 yrs (i.e., 25 to 35% of energy) compared with adults (i.e., 20 to 35% of energy). Despite this, many parents and children restrict dietary fat for health reasons. 相似文献9.
M. Kruger C. M. Smuts A. J. S. Benadé J. E. Fincham C. J. Lombard E. A. Albertse K. J. van der Merwe 《Lipids》1992,27(10):733-739
The effects of the degree of unsaturation and of the amount of dietary fat on low density lipoprotein (LDL) concentration
and composition were determined in vervet monkeys. Diets with fat contents of 41, 31 and 18% energy, each with a low and a
high polyunsaturated to saturated fatty acid ratio (P/S; 0.27–0.38 and 1.13–1.47) were fed to six female vervet monkeys for
two months. Another six females were given a low fat, high P/S diet for the same period of time, to serve as a reference.
The cholesterol contents of the diets were low (21–33 mg per day) and relatively constant. LDL cholesterol concentrations
decreased significantly (P≤0.01) when the dietary fat content decreased from 31 to 18% of energy. The dietary P/S ratio only affected LDL cholesterol
concentrations during moderate (31% of energy) fat intake, where LDL cholesterol increased (P≤0.01) with a decrease in dietary P/S. Substantial individual variations were observed in LDL cholesterol concentration responses
to dietary fat changes. The changes in LDL cholesterol concentrations were the result of changes in the concentration of LDL
particles, as the molecular composition did not differ significantly between dietary periods. The high density lipoprotein
choelsterol and the plasma triacylglycerol concentrations were not influenced by the dietary fat changes. During the high
P/S diets, the percentage of 18∶2 (linoleic acid) increased (P≤0.01) and that of 18∶1 (oleic acid) decreased (P≤0.01) in LDL esterified cholesterol, as compared to the low P/S diets. In adipose tissue triacylglycerol the percentage of
18∶2 was three times higher (P≤0.01) during the high P/S diets than during the low P/S diets. A decrease in the amount of dietary fat (from 31 to 18% of
energy) was associated with an increase in the percentage of 18∶1 in LDL esterified cholesterol. 相似文献
10.
Effect of Dietary Fat on Plasma Level of Lecithin, Lysolecithin and Sphingomyelin in Man Reduction of fat content of the diet leads to a decrease in total phosphatide level in plasma, mainly due to alteration in the lecithin fraction. The level of lecithin in experimental persons fed a formula diet containing 25% of the total energy as fat was distinctly lower than in those fed 33% of the total energy as fat. The P/S quotient at a fat level of 33% of total energy had still an influence on the lecithin level in blood. At a fat level of 25% of total energy, modification of the fat components did not alter the serum lecithin level to a statistically significant extent. The plasma level of lysolecithin decreased with reduction in the proportion of dietary fat, however, it did not vary with different types of fat. The level of sphingomyelin was almost the same for the two formula diets and it did not vary either by reduction in the proportion of fat or by modification of the fat components. 相似文献
11.
Ivan C. Burkow Per Moen Kersti Øverbø 《Journal of the American Oil Chemists' Society》1992,69(11):1108-1111
Chemiluminescence based on light emission from excited oxygen species,e.g. singlet oxygen and triplet carbonyls, has been used to measure the oxidative rencidity of fish oils. The luminescence was
recorded after sodium hypochlorite addition to the oils dissolved intert-butanol. In addition to high sensitivity and ability to detect small changes in rancidity, the method is fast and may be
used as a supplement to the standard chemical methods for quality assessment and antioxidant evaluation. However, care has
to be taken in interpretation of the chemiluminescence data of different fish oils, as the light emission depends on both
the composition and the rancidity level of the oil. The autoxidized oils were also characterized by peroxide value, thiobarbituric
acid value, anisidine value, Kreis rancidity index, iodine value, ultraviolet measurements, capillary gas chromatography,
size-exclusion chromatography and sensoric evaluation. 相似文献
12.
Milk fat fractionation today: A review 总被引:2,自引:0,他引:2
E. Deffense 《Journal of the American Oil Chemists' Society》1993,70(12):1193-1201
Although anhydrous milk fat (AMF) has excellent properties, its variable physicochemical properties and its lack of functionality
restrict its uses in the food industry. A technology involving dry fractionation of AMF has been developed, and its attributes
include selectivity, reliability and general application. Combining two simple and reliable technologies,i.e., multi-step fractionation and blending, it is possible to overcome functionality problems and the seasonal variations of
AMF.
Lecture presented at the joint meeting of the International Society for Fat Research and the American Oil Chemists’ Society
in Toronto, May 10, 1992. 相似文献
13.
The dietary intake of EFA and long-chain PUFA (LCPUFA) by women with (n=14) and without (n=31) gestational diabetes mellitus (GDM) was determined by repeated 24-h recalls. Women with GDM consumed significantly more
energy as fat compared with women who had uncomplicated pregnancies; absolute dietary fat did not differ. Dietary n−3 LCPUFA
was substantially lower than the current recommendation for pregnancy, whereas intake of saturated FA (SFA) exceeded it. We
conclude that replacing dietary sources of SFA with those of EFA and LCPUFA, especially n−3 LCPUFA, would benefit the dietary
fat profiles of all pregnant women. 相似文献
14.
Simone Ast 《European Journal of Lipid Science and Technology》1995,97(10):389-392
Lipolytic Fat Deterioration in Carry Spice Mixes – Suitability of Fluorometric Lipase Determination for Quality Evaluation To improve quality and shelf life of fat containing dry mixtures (e.g. soups, sauces) treated spice mixtures are increasingly used in the industry. By a hydrothermic treatment (i.e. moist heat/steam) an enzyme inactivation of spices beside a germ reduction is observed. The evidence for Lipase activities (which cause hydrolytic fat deterioration) in curry mixtures could be shown within 3 different methods: A Fluorometric method based on 4-methylumbelliferylesters as substrates is suitable for proving a thermic treatment in different curry spice mixtures. When compared to a true Lipase measurement (incubation test with coconut fat as substrate) and to a socalled Esterase-test according to Purr it could be clarified that all 3 methods give corresponding results. Treated curry mixtures are almost fully inactivated, whereas untreated curry mixtures show considerable lipase activity. With the fluorometric method, which is quickly carried out, very low residual activities are shown. This is not possible with the Esterase-test. The incubation test also sensitively demonstrates Lipase, but takes a longer time to evaluate. 相似文献
15.
G. Wolfram 《European Journal of Lipid Science and Technology》1994,96(2):39-41
Fat and Nutrition - The Point of View of the DGE Fat is an important energy source because of its high energy density. Moreover fat in food is carrying fat soluble vitamins and essential fatty acids. Fat contributes to the taste of dishes and increases the acceptance of food. Energy density of fat is important for the high energy demand of children and heavy workers. The supply of fat soluble antioxidative vitamins is of increasing importance. The influence of the amount and the quality of fat on lipoproteins in blood and coronary risk as well as epidemiological data on the relation of a high fat intake and the risk of different kinds of cancer are of importance. Fat intake is a critical factor in nutrition and should be intensively monitored with respect to upper and lower limits. 相似文献
16.
H. Tributsch J. C. Bennett 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1981,31(1):627-635
Sixteen metal sulphides with widely differing solid state, chemical and electrochemical properties have been investigated with respect to their suitability as an energy source for Thiobacillus ferrooxidans. The most critical rate-determining parameter for bacterial oxidation (in the absence of any electron acceptors, e.g. Fe3+) was the solubility product of the sulphide. Deviations from the systematic dependence are, however, observed when a large concentration of the holes are present in the semiconducting sulphide (p-type conduction), or when holes are generated through electron extraction from the sulphide surface (e.g. by Fe3+). The experimental results are consistent with a mechanism in which Th. ferrooxidans utilises H+ and Fe3+ as catalytic agents which break surface bonds by chemical and electrochemical mechanisms, respectively. They are subsequently recycled while the bacterium oxidises the generated surface products, — SHδ and So, etc., to sulphate. On the basis of the derived mechanism it should be possible to estimate and predict the suitability of sulphides for bacterial oxidation and to analyse the influence of crystalline quality and impurities, as well as the composition of the solution, on the rate of oxidation. 相似文献
17.
This study evaluated the effects of conjugated linoleic acids (CLA) on tissue fatty acid composition and ex vivo prostaglandin E2 (PGE2) production in rats given diets varying in n-6 and n-3 fatty acids. Four groups of rats were given a basal semipurified diet
(AIN-93G) containing 70 g/kg of added fat for 42 d. The fat treatments were formulated to contain CLA (0 vs. 10 g/kg of diet)
and n-6 (soybean oil having an n-6/n-3 ratio of 7.3) and n-3 fatty acids (menhaden oil+safflower oil having an n-6/n-3 ratio
of 1.8) in different ratios in a 2×2 factorial design. Fatty acids in liver, serum, muscle, heart, brain, spleen, and bone
(cortical, marrow, and periosteum) were analyzed by capillary gas-liquid chromatography. The various dietary lipid treatments
did not affect growth; however, CLA improved feed efficiency. The CLA isomers were found in all rat tissues analyzed although
their concentrations varied. Dietary CLA decreased the concentrations of 16∶1n−7, 18∶1, total monounsaturates and n−6 fatty
acids, but increased the concentrations of n−3 fatty acids (22∶5n−3 and 22∶6n−3), and saturates in the tissues analyzed. Ex vivo PGE2 production in bone organ culture was decreased by n−3 fatty acids and CLA. We speculate that CLA reduced the concentration
of 18∶1 fatty acids by inhibiting liver Δ9-desaturase activity. The fact that CLA lowered ex vivo PGE2 production in bone organ culture suggests that these conjugated fatty acids have the potential to influence bone formation
and resorption. 相似文献
18.
Martin R. L. Scheeder Karola R. Glser Barbara Eichenberger Caspar Wenk 《European Journal of Lipid Science and Technology》2000,102(6):391-401
Two feeding experiments (i, ii) were conducted to investigate the influence of different dietary fats on the fatty acid (FA) composition of phospholipids as well as meat quality in pigs. In each experiment 12�4 siblings of Swiss Landrace or Large White breed were allocated to one of four feeding treatments according to sex, breed, and litter and fattened from about 25 to 105 kg liveweight. Pigs were fed a control diet (barley, wheat, soybean meal) or the control diet supplemented with 7% pork fat, 4.95% olive oil or 3.17% soybean oil (i) or 5% of olein or stearin fraction of pork fat or hydrogenated fat (ii). The dietary FA composition was reflected in the FA composition of phospholipids in M. long. dorsi and triceps brachii. However, the unsaturated to saturated ratio was not affected by the dietary intake of polyunsaturated FAs and was only slightly increased by the olive oil supplementation. Trans FAs including conjugated linoleic acid were incorporated into phospholipids only to a small extent. The dietary altered fatty acid composition of phospholipids did not cause any effect on pH, cooking loss, texture, or colour of pork, but meat quality as well as the proportion of saturated FA, arachidonic acid, and n‐3 fatty acids were significantly influenced by genetic effects. 相似文献
19.
Trans-10, cis-12 conjugated linoleic acid (CLA) is a potent inhibitor of milk fat synthesis in the cow and similarly reduces milk fat in rodents. The objective of this study was to determine whether dietary fat can overcome CLA inhibition of milk fat concentration in lactating mice. Wild type C57Bl/6J mice (n = 31) were fed semipurified diets containing either low fat (LF; 4% fat) or high fat (HF; 23.6% fat) starting 4–6 days postpartum. Dietary fat was increased by inclusion of high oleic sunflower oil. After 2 days on the experimental diets, lactating dams were orally dosed with either water (control) or trans-10, cis-12 CLA (20 mg/day) for 5 days. CLA treatment decreased pup growth similarly in both HF and LF diets. Milk fat percent was increased over 16% by the HF diet and decreased over 12% by CLA, but there was no interaction of dietary fat and CLA. Both CLA and the HF diet reduced the proportion of short- and medium-chain fatty acids that originate from de novo synthesis, and there was no interaction of diet and CLA. CLA had no effect on the percent of preformed fatty acids, but the HF diet increased their abundance. Dietary fat and CLA both modified mammary expression of lipogenic enzymes and regulators, but no interactions were observed. In conclusion, CLA reduced milk fat concentration and litter growth, but these effects were not overcome by increased dietary fat from high oleic sunflower oil. CLA inhibition of milk fat in the mammary gland is not substrate dependent, and the mechanism is independent from dietary supply of oleic acid. 相似文献
20.
Gregersen S Thomsen JL Jeppesen PB Alstrup KK Brock B Pedersen SB Kristensen K Hermansen K 《Lipids》2003,38(5):513-517
The aim of the present study was to elucidate whether the qualitative compositiion of dietary fat influences plasma leptin
and adipose tissue ob gene expression differentially. Two high-fat diets and a diet rich in carbohydrate were each administered
both ad libitum and with a 25% energy restriction. The high-fat diets contained 58 energy percent as either monounsaturated FA (MUFA) or
saturated FA (SAFA), whereas the carbohydrate-rich diet (CH) contained 7 energy percent as fat. We aimed at obtaining the
same final weight for the animals in the ad libitum group as in the energy-restricted groups. This goal was reached at he same time (days 22–24) for all groups except for the
ad libitum animals fed on saturated fat (day 36). The plasma leptin concentrations on ad libitum CH and MUFA diets did not differ significantly (24.3 ± 2.1 and 34.7 ± 6.7 ng/mL, respectively) whereas the saturated fat
diet caused a lower concentration (13.9 ± 1.9 ng/mL; P < 0.05). Interestingly, no differences in plasma leptin levels between groups were seen in the energy-restricted groups (mean
8.0 + 1.0 ng/mL). The type of diet did not alter the ob gene expression in intraabdominal white adipose tissue; however, a
lower expression level was found in the energy-restricted groups. The percentage of body fat in the three ad libitum fed groups did not differ (23 ± 1%). Thus, short-term administration of a diet rich in SAFA suppresses circulating leptin
levels without altering the adipose tissue ob gene expression. This indicates that saturated fat may alter protein handling
by adipose tissue or the whole body clearance of leptin. 相似文献