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1.
An examination of the suitability of an alkalimetric method for the determination of free fatty acid (FFA) contents in fats,
oils, and lipid extracts was conducted by comparing AOCS method Ca 5a-40 with a method based on a Chromarod-latroscan thin-layer
chromatography-flame-ionization detector (TLC-FID) system. The FFA contents determined by the alkalimetric method were consistently
higher than the genuine FFA contents obtained by the latroscan TLC-FID method. Phospholipids were found to be the major components
that contributed to the alkali-titratable, nongenuine FFA in the total FFA determined alkalimetrically. Contributions from
other polar lipid components were smaller, but they dominated as the proportion of phospholipids fell. The other alkali-titratable
polar components may include oxidized lipids and their by-products bound to protein fragments. The accurate determination
of FFA contents by alkalimetric methods may only be applicable to those commercially refined fats and oils that contain negligible
amounts of phospholipids. Corrections for the alkalimetrically determined FFA contents should be made for those fats and oils
with relatively high phospholipid contents by correlating the nongenuine FFA contents and the phospholipid contents. 相似文献
2.
R. G. Ackman 《Journal of the American Oil Chemists' Society》1966,43(6):385-389
From data obtained in this laboratory two empirical formulas have been developed which correlate polyunsaturated fatty acids
indicated by GLC analyses with iodine values of marine oils or their fatty acid methyl esters. These formulas have been applied
to data from the literature with good agreement. It is suggested that these formulas function only with fats having the basic
composition of marine lipids, which consist principally of saturated, monounsaturated and very highly unsaturated fatty acids.
The presence of modest amounts of dienoic and trienoic fatty acids such as are found in freshwater aquatic life and in land
animals makes the formulas inapplicable, suggesting their use to distinguish marine fish oils and lipids from other types.
The formulas could be particularly useful in technological applications of marine oils where a rapid and approximate knowledge
of amount of polyunsaturated fatty acids is desirable. 相似文献
3.
Medium chain triglycerides and structured lipids 总被引:16,自引:4,他引:12
Vigen K. Babayan 《Lipids》1987,22(6):417-420
Lipids are an essential component of our body composition and necessary in our daily food intake. Conventional fats and oils
are composed of glycerides of long chain fatty acids and are designated as long chain triglycerides (LCT). Body fat as well
as the fats and oils in our daily intake fall into this category. In enteral and parenteral hyperalimentation, we can identify
such LCT fats and oils. Soy, corn, safflower and sunflowerseed oils are typical of the LCT oils.
In the search for alternative noncarbohydrate fuels, medium chain triglycerides (MCT) are unique and have established themselves
in the areas of malabsorption syndrome cases and infant care and as a high energy, rapidly available fuel. Structure lipids
with a MCT backbone and linoleic acid built into the triglyceride molecule have been developed to optimize the triglyceride
structure that is best for patients, particularly the critically ill. Structured lipids with built-in essential fatty acid
components or other polyunsaturated fatty acids promise greater flexibility in patient care and nitrogen support. 相似文献
4.
Use of Essential Oils From Various Plants to Change the Fatty Acids Profiles of Lipids Obtained From Oleaginous Yeasts
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We studied the ability of seven essential oils to alter the fatty acid composition of lipids produced by an oleaginous yeast Rhodosporidium toruloides. All of the essential oils, except thyme, significantly increased the stearic acid content of the lipids. The amount of essential oils in the media determined the fatty acid composition obtained. Subsequently, we studied the effect of the major monoterpenes present in these essential oils. When R. toruloides was grown on limonene, a major monoterpene in orange essential oil, the composition of lipid obtained was found to be quite similar to natural orange essential oil. This proved that limonene has a major role in the changes in fatty acid profiles of the lipids. The effect of orange essential oil on another oleaginous yeast, Cryptococcus curvatus, was also carried out. Although the effect of the essential oil on the fatty acid composition and biomass (cell mass) was similar for both these two yeasts, the reduction of the activity of some enzymes involved in the metabolic pathways was quite different. From these results, it can be concluded that the effect of essential oils differs with species and it is possible to produce lipids with alternate fatty acid profiles suitable for different applications and with good market value. 相似文献
5.
Rafael Garcs Enrique Martínez‐Force Joaquín J. Salas Miguel A. Bootello 《Lipid Technology》2012,24(3):63-65
New high‐oleic high‐stearic sunflower lines produce oils that could be a source of disaturated triacylglycerol alternatives to tropical fats. These oils can be fractionated to produce stearins enriched in stearic acid with physical properties similar to cocoa butter and other confectionary fats without hydrogenation or transesterification. These fats can be produced in temperate countries from a well‐established crop like sunflower, and represent a healthy source of saturated fatty acids. 相似文献
6.
Katharine J. Hivon Susie N. Hagan Edith B. Wile 《Journal of the American Oil Chemists' Society》1964,41(5):362-366
The fatty acid compositions of some food fats and oils were determined by gas-liquid chromatography (GLC) before and after
application of reagents and conditions of some extraction procedures. The extraction procedures studied had a nonsignificant
effect on the fatty acid compositions. Procedures leading to methyl ester formation through a series of room temp reactions
were selected over procedures requiring higher temp reactions, on the basis of yield of products, fatty acid compositions
of food lipids of simple composition, or both. These procedures were then used to prepare some food fats and oils for analysis
by GLC and the fatty acid compositions determined in this manner are presented.
Food Composition Laboratory, ARS, USDA. 相似文献
7.
Terry K. Smith 《Lipid Technology》2015,27(1):7-10
Edible oils and fats are among the most abundant cooking ingredients in the world, and are an important part of a healthy balanced diet, especially if they are high in omega‐6 and omega‐3 polyunsaturated fatty acids. Rather than just the total fatty acid compositions, the analysis of individual lipid species within these oils and fats has become increasingly important. Within the past decade several mass spectrometric lipidomics methods have been adapted and applied to the analysis of edible oils and fats. These methodologies are vital for the analysis of a plethora of lipid species that will be important for numerous health and sustainability issues in the future. 相似文献
8.
C. Ratledge 《European Journal of Lipid Science and Technology》1984,86(10):379-389
Three areas where biotechnology is applicable to the oils and fats industry are described. 1. Biotechnology and oil plants includes the cloning of high-yielding trains of oil palms to yield progeny in large numbers relatively quickly. Mutation of oilseeds to change the fatty acid composition is also being carried out in various laboratories. 2. Biotechnology with enzymes encompasses the use of microbial lipases for the interesterification of triacylglycerols to form cocoa butter substitutes, as well as the use of lipases to hydrolyse selectively particular fatty acyl esters. Some industrial developments in these areas appear imminent. 3. Biotechnology with micro-organisms can be seen as an alternative means of producing oils and fats to existing routes though the economics are against such processes being taken up for all but the most expensive oils and fats. A range of oils can, however, be produced by bacteria, algae, yeasts and moulds. Micro-organisms can also be used to transform alkanes and fatty acids to provide various fatty acid derivatives which could be of value. The biochemistry behind lipid accumulation is described. This provides an understanding of the regulatory enzymes which need to be controlled in order to achieve high accumulations of lipids. From such information, it then becomes possible to consider metabolic manipulation of the organism to improve its fat yield. By extension of these arguments, possible opportunities for genetic engineering into both micro-organisms and plants then become evident. 相似文献
9.
The application of wall-coated open-tubular (capillary) gasliquid chromatographic columns to some current analytical problems in fat research is described. The liquid phase SILAR-5CP in commercially available stainless steel columns has been found to be particularly suitable for rapid screening of fats and oils for total docosenoic acid without interference from other components. Differentiation of two important 22:1 isomers (erucic acid from vegetable oils and cetoleic acid from marine oils) is possible and the erucic acid content of an oil or fat can be estimated in approximately 20 minutes. The effects of partial hydrogenation of fats on the gas-liquid chromatography of these fatty acid structural details are reviewed. The use of other liquid phases such as butanediolsuccinate polyester, and the advantages of SILAR-7CP for study of geometrical isomers in wall-coated open-tubular columns are discussed briefly, and also the potential of support-coated open-tubular columns for similar analyses of longer-chain fatty acids. 相似文献
10.
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
11.
The fatty acids recovered from the triglycerides and wax esters of common northwest Atlantic copepods are compared with the
fatty acids of wax esters recovered intact from certain fish skin and body lipid, and from commercial fish oils. The fish
species, herring, capelin and mackerel, all feed on copepods, and many resemblances of the copepod lipid fatty acids to those
of a previous analysis of similar copepods suggest that the basic dietary fat input for these fish may be quite constant.
The two copepod fatty acid analyses differed quantitatively in triglyceride 20∶1 and 22∶1 and also in 20∶5ω3 and 22∶6ω3, confirming
the primary role of the wax esters in copepods. Selectivity factors are discussed in comparing the copepod wax ester fatty
acids with the fatty acids of the wax esters recovered intact from the fish lipids and oils. The basic role of copepods in
supplying all types of fatty acids to fish depot fats is considered to be strongly supported by these findings. 相似文献
12.
High-fat ketogenic diets are used to treat intractable seizures in children, but little is known of the mechanism by which
these diets work or whether fats rich in n−3 polyunsaturates might be beneficial. Tissue lipid and fatty acid profiles were
determined in rats consuming very high fat (80 weight%), low-carbohydrate ketogenic diets containing either medium-chain triglyceride,
flaxseed oil, butter, or an equal combination of these three fat sources. Ketogenic diets containing butter markedly raised
liver triglyceride but had no effect on plasma cholesterol. Unlike the other fats, flaxseed oil in the ketogenic diet did
not raise brain cholesterol. Brain total and free fatty acid profiles remained similar in all groups, but there was an increase
in the proportion of arachidonate in brain total lipids in the medium-chain triglyceride group, while the two groups consuming
flaxseed oil had significantly lower arachidonate in brain, liver, and plasma. The very high dietary intake of α-linolenate
in the flaxseed group did not change docosahexaenoate levels in the brain. Our previous report based on these diets showed
that although ketosis is higher in rats consuming a ketogenic diet based on medium-chain triglyceride oil, seizure resistance
in the pentylenetetrazol model is not clearly related to the degree of ketosis achieved. In combination with our present data
from the same seizure study, it appears that ketogenic diets with widely differing effects on tissue lipids and fatty acid
profiles can confer a similar amount of seizure protection. 相似文献
13.
Ozan Nazim Ciftci Roman Przybylski Magdalena Rudzińska 《European Journal of Lipid Science and Technology》2012,114(7):794-800
Composition of fatty acids, tocopherols, sterols, and TAGs in the lipids of flax, perilla, and chia seeds were investigated where lipid content was at 45, 40, and 35%, respectively. α‐Linolenic acid (ALA) dominated among fatty acids in all oils and accounted for 58.2, 60.9, and 59.8% in flax, perilla, and chia, correspondingly in these three oils trilinolenin was the main TAG found at 19.7, 22.6, and 21.3%. Triunsaturated TAGs accounted for 77.9, 77.5, and 74.5% of the total amounts in flax, perilla, and chia oils. Contents of tocopherol were at 747 in flax, 734 in perilla, and 446 mg/kg in chia seed lipids. γ‐Tocopherol was the dominating isomer contributing 72.7% in flax, 94.3% in perilla, and 94.4% in chia to the total amount of tocopherols. Flaxseed lipids contained 25.6% of plastochromanol‐8, derivative of γ‐tocotrienol with longer side chain; perilla and chia oils contained only 1.4% of it. Phytosterols were present at 4072, 4606, and 4132 mg/kg in those seeds, respectively. Among sterols, β‐sitosterol dominated and was found at 35.6, 73.3, and 49.8% of the total amounts of sterols in flax, perilla, and chia seed lipids. All of the investigated oilseeds have an excellent nutritional quality and can be a potential source of nutraceutical fats which can enrich diet in linolenic acid and other functional components. 相似文献
14.
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
15.
Feiyun Yang Bao Zhang Baiting Chen Nafei Yang Ruigang Wang Xiujuan Zhang Guojing Li 《Journal of the American Oil Chemists' Society》2022,99(3):203-213
As important oil crops in Inner Mongolia, sunflower, and flaxseed had distinct lipid profiles in seeds. As an emerging cash crop, Hibiscus manihot L. has strong potential market competitiveness. In this study, the lipidome, fatty acid composition and quality characteristics of flaxseed, H. manihot L., and sunflower seed oils were analyzed and compared. A total of 270 distinct lipids were identified and analyzed with an emerging detection approach—lipidomics, which illustrated the tremendous difference among the samples. triacylglycerol, diacylglycerol and polar lipids were the most abundant lipids in all samples. H. manihot L. seeds contained higher saturated and monounsaturated fatty acids and lower polyunsaturated fatty acids. H. manihot L. seed oil had the longest oxidative stability index time, high content of vitamin E and total phenolics, while flaxseed oil embodied the lowest oxidative stability. The peroxide value and acid value of the three oils were within the allowable range of Chinese national standards. 相似文献
16.
A relatively simple method is detailed for the routine isolation and estimation of oxofatty acids (OFA) in lipids. The lipid
in cyclohexane is transmethylated in a two-phase, 3.5 min procedure, and the carbonyls in the methyl ester fraction are derivatized
with 2,4-dinitrophenylhydrazine (DNPH) in the presence of monochloroacetic acid (MCA). The derivatives are fractionated on
alumina, and the OFA fraction is obtained and evaluated spectrophotometrically. A large variety of animal, plant, and marine
lipids contained OFA ranging from <1 to >50 μmoles/g. Data also show that (a) OFA are formed in naturally oxidizing fats and
oils, and (b) strongly acidic conditions can cause elaboration of OFA in hydroperoxidized fats and oils. 相似文献
17.
Zhong-Yuan Liu Da-Yong Zhou Kanyasiri Rakariyatham Hong-Kai Xie De-Yang Li Bei-Wei Zhu Fereidoon Shahidi 《Journal of the American Oil Chemists' Society》2019,96(12):1367-1377
The current study shows the compositional changes and oxidation development of clam (Ruditapes philippinarum, R. philippinarum) lipids and frying oils when subjected to different processing conditions. Parameters measured include acid value, peroxide value (POV), thiobarbituric acid-reactive substances (TBARS), total oxidation (TOTOX), lipid classes, fatty acid composition, phosphatidylcholine (PC), and phosphatidylethanolamine (PE) contents together with major glycerophospholipid (GP) molecular species. Deep-fat frying increased triacylglycerol (TAG) content and decreased the contents of PC, PE, and GP molecular species in clam in a time-dependent manner. Meanwhile, minor amounts of free fatty acids, diacylglycerols, monoacylglycerols, and polar lipids were detected in frying oils, indicating lipid migration between the clam and frying oils. The time-dependent increase of POV, TBARS, and TOTOX in fried clams and frying oils with concurrent reduction of docosahexenoic acid and eicosapentaenoic acid indicates extensive oxidative degradation of clam lipids. Moreover, the moisture-rich clam aggravated the deterioration of frying oils. Consequently, deep-fat frying significantly altered the lipid profile and decreased the nutritional value of clams. 相似文献
18.
Summary Characteristics and fatty acid compositions of the lipid components of the main fractions (germ, starch, gluten, and fiber)
obtained in the wet milling of corn and grain sorghum kernels have been determined.
The various lipids exhibited differences in chemical characteristics and fatty acid composition. These differences were found
to be similar in both grains. Germ fats were the most unsaturated, contained the least free fatty acids and the least unsaponifiable
matter. Starch fats were 70 to 90% free fatty acids and contained large amounts of palmitic acid. Gluten and fiber fats contained
up to 32% unsaponifiables and about 20% free fatty acids. 相似文献
19.
Klaus Eder Manfred Kirchgessner 《European Journal of Lipid Science and Technology》1999,101(5):178-184
Several studies demonstrated that dietary oxidized oils markedly affect the vitamin E status and alter the fatty acid composition of tissue lipids in animals. It must however be emphasized that highly oxidized oils reduce the feed intake of animals, which makes it difficult to interpret the results. Therefore, the present study used a moderately thermoxidized soybean oil (peroxide value: 75 mEq O2/kg), having a similar fatty acid composition as fresh soybean oil (peroxide value: 9.5 mEq O2/kg) which was used as control. Moreover, according to a bifactorial design, two different vitamin E supplementary levels (11 vs. 511 mg α-to-copherol equivalents per kg diet) were used. The experiment was conducted with male Sprague-Dawley rats. The feeding period lasted for 40 days. In order to assess the vitamin E status, the vitamin E concentrations in plasma, liver, heart, kidney, and adipose tissue were determined. The vitamin E supply had a pronounced effect on the vitamin E concentrations of those tissues whereas the type of fat had only a slight effect. The fatty acid composition of total lipids from liver, erythrocytes, and low-density lipoproteins was also only slightly influenced by the oxidized fat. The osmotic fragility of erythrocytes was even reduced by feeding the oxidized oil. With a low vitamin E supply, the in vitro susceptibility of low-density lipoproteins to lipid peroxidation was slightly increased by feeding the oxidized oil. In contrast, with a high vitamin E supply, there was no adverse effect of the dietary oxidized oil on the susceptibility of low-density lipoproteins to lipid peroxidation. Feeding the oxidized oil, however, increased the concentrations of malondialdehyde in low-density lipoproteins suggesting an increased in vivo lipid peroxidation. Therefore, it cannot be ruled out that moderately oxidized dietary fats increase the atherogenicity of low-density lipoproteins. In contrast, a moderately oxidized oil scarcely affected the vitamin E status and the fatty acid composition of tissue lipids. 相似文献
20.
Seraphim Papanikolaou George Aggelis 《European Journal of Lipid Science and Technology》2011,113(8):1052-1073
The process of lipid accumulation in the oleaginous yeasts cultivated in various fermentation configurations when either sugars and related compounds or hydrophobic substances are used as substrates is presented and kinetic models describing both de novo and ex novo lipid accumulation are analyzed. Technological aspects related with single cell oil (SCO) produced by oleaginous yeasts are depicted. The influence of culture parameters upon lipid production process is presented. Lipid production has been studied in batch, fed‐batch, and continuous cultivation systems using yeasts belonging to the species Lipomyces starkeyi, Rhodosporidium toruloides, Apiotrichum curvatum, Candida curvata, Cryptococcus curvatus, Trichosporon fermentans, and Yarrowia lipolytica. The potentiality of yeasts to produce SCO as starting material of 2nd generation biodiesel is indicated and discussed. Of significant importance is also the utilization of yeast lipids as substitutes of high added value exotic fats (e.g., cocoa butter). Lipid produced by the various yeasts presents, in general, similar composition with that of common vegetable oils being composed of unsaturated fatty acids, whereas cocoa butter is principally composed of saturated fatty acids, consequently the various strategies that are followed in order to increase the cellular saturated fatty acid content of the yeast lipid are presented and comprehensively discussed. 相似文献