共查询到20条相似文献,搜索用时 15 毫秒
1.
C. Adhikari H. E. Snyder T. W. Kwon P. K. Clark 《Journal of the American Oil Chemists' Society》1992,69(11):1141-1145
By varying the extracting conditions, it may be possible to produce high-quality, low-phosphorus and low-free fatty acid (FFA)
oil extracted from water or mechanically damaged soybeans. The variability in phospholipids and FFA was studied in oil extracted
by an alternative process from undamaged, damaged and aged soybeans subjected to various changes. Forrest and Hutcheson cultivars
were used, and extractions were from finely ground flour rather than from flakes. Freezing caused the maximum increase in
FFA and phosphorus levels compared to other levels in damaged or undamaged soybeans, but the levels were reasonable compared
to flake extraction. Phosphorus and FFA increased when storage temperatures went from 25 to 45°C, extraction temperatures
from 25 to 50°C and moisture of the flour from 6 to 10%. However, the storage time of soybeans with initially high moisture
(20%) did not have a marked influence on FFA and phosphorus levels. Immediately after grinding moisture of the flour elevated
or lowered the phosphorus level to a great extent, although it had little influence on the FFA level. Phosphatidic acid and
phosphatidylcholine were identified as the main phospholipids present when total phosphorus was low in extracted oil. The
time taken for the flour to dry to 6% moisture (after grinding and before it was extracted) was critical. The alternative
extraction process moderated the expected increase in FFA and phospholipids as the result of soybean damage. 相似文献
2.
Comparison of fatty acid composition of domestic and imported margarines and frying fats in Bulgaria
Ilko Marekov Roumyana Tarandjiiska Svetlana Panayotova Nelly Nikolova 《European Journal of Lipid Science and Technology》2002,104(7):410-418
A total of 82 dietary fats sold on the Bulgarian market in the period 1995—2000 were analyzed. The samples included 68 table margarines (50 of which were imported), 10 frying fats (6 imported) and 4 salad dressings (all imported). A validated analytical method, thin‐layer chromatography‐AgNO3‐densitometry, was used. It enabled direct determination of all fatty acid groups, differing by degree of unsaturation and double bonds geometry. Low levels of trans fatty acids (TFA) down to 0.1% of the total for mono trans‐trienoic (Tcct) and mono trans‐dienoic (Dct), and down to 0.2% for trans‐monoenoic (Mt) were quantitated, with an error under 3% and a standard deviation of 0.1—1.5. The total content of TFA in table margarines varied from 0 to 26.9% with a mean value of 8.6 ± 7.2% for imported and 1.6 ± 3.4% for Bulgarian samples. Saturated fatty acids (SFA) content varied from 11.5 to 45.7%, with a mean value of 25.4 ± 5.7% for imported and 26.9 ± 5.2% for Bulgarian margarines. A general trend of lower levels of TFA and SFA in imported margarines was observed over the studied period. Additionally, the content of individual saturated fatty acids was determined by gasliquid chromatography in 37 of all studied samples. 相似文献
3.
M. Suutari A. Rintamäki S. Laakso 《Journal of the American Oil Chemists' Society》1996,73(8):1071-1073
The effect of environmental temperature on fatty acid contents of major lipid classes was determined inLipomyces starkeyi at 30, 20, and 10°C. When the temperature was reduced from 30 to 20°C, the linolenic acid content increased in phosphatidylcholine
but fell with further reduction to 10°C. The relative contribution of phosphatidylcholine and phosphatidylethanolamine that
contained the next lowest-melting fatty acids, palmitoleic and linoleic acids, increased on lowering the temperature from
20 to 10°C and, concomitantly, the combined phosphatidylinositol and phosphatidylserine fraction decreased, and triacylglycerols
were accumulated. 相似文献
4.
Lenka A. Taylor Vittorio Ziroli Ulrich Massing 《European Journal of Lipid Science and Technology》2009,111(9):912-919
Phospholipids are recognised as an important source and transport form for metabolically active fatty acids. Therefore, detailed analysis of fatty acid profiles in plasma phospholipids as marker for dietary habits or interventions gains more and more importance. Appropriate analytical methods described so far are either expensive or susceptible to handling errors. We developed a method to separate plasma phospholipids by acetone fractionation combined with SPE in order to analyse the fatty acid compositions in phospholipid fractions of human plasma by GC analysis. The method has been validated in order to be applied to the routinely performed analysis of the samples of patients who will be participating in a dietary supplement study. The method presented here was successfully validated and is stable, efficient and reproducible. It can be used in a routine fashion to deliver the fatty acid profile [palmitic acid (16:0), heptadecanoic acid (17:0), stearic acid (18:0), oleic acid (18:1n‐9), linoleic acid (18:2n‐6), linolenic acid (18:3n‐3), arachidonic acid (20:4n‐6), eicosapentaenoic acid (20:5n‐3) and docosahexaenoic acid (22:6n‐3)] in plasma phospholipid samples. Using a sample volume of 500 µL, recovery of plasma phospholipids is 92 ± 11%; LOQ is 2.2 µg fatty acid/mL. A set of samples from cancer patients and healthy individuals was analysed and confirmed the applicability of the described method. 相似文献
5.
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
6.
The oxidative stabilities of one canola oil and six soybean oils of various fatty acid compositions were compared in terms
of peroxide values, conjugated dienoic acid values and sensory evaluations. Two of the soybean oils (Hardin and BSR 101) were
from common commercial varieties. The other four soybean oils were from experimental lines developed in a mutation breeding
program at Iowa State University that included A17 with 1.5% linolenate and 15.2% palmitate; A16 with 2% linolenate and 10.8%
palmitate; A87-191039 with 2% linolenate and 29.6% oleate; and A6 with 27.5% stearate. Seed from the soybean genotypes was
cold pressed. Crude canola oil was obtained without additives. All oils were refined, bleached and deodorized under laboratory
conditions with no additives and stored at 60°C for 15 days. The A17, A16, A87-191039 and A6 oils were generally more stable
to oxidation than the commercial soybean varieties and canola oil as evaluated by chemical and sensory tests. Canola oil was
much less stable than Hardin and BSR 101 oils by both chemical and sensory tests. The peroxide values and flavor scores of
oils were highly correlated with the initial amounts of linolenate (r=0.95, P=0.001). Flavor quality and flavor intensity
had negative correlations with linolenate, (r=−0.89, P=0.007) and (r=−0.86, P=0.013), respectively. 相似文献
7.
J. C. Martin F. Lavillonnière M. Nour J. L. Sébédio 《Journal of the American Oil Chemists' Society》1998,75(12):1691-1697
The influence of isomeric triacylglycerols (TG) containing 18:3n-3 and 18:2n-6 on the formation of cyclic fatty acid monomers
(CFAM) after heat treatment was assessed. Diacid TG, containing linoleic acid (L) or linolenic acid (α-Ln) along with palmitic
acid (P), and positioned either in the central position (PLP and PLnP, respectively), or in one of the two outer positions
(PPL and PPLn, respectively) were synthesized. Monoacid TG of trilinolein and trilinolenin mixed with tripalmitin were also
prepared. The CFAM formed after heating were analyzed after total hydrogenation. The results obtained with the model TG were
compared to another model consisting of a canola oil and its randomized counterpart. In diacid TG, the location of α-Ln in
the central position of the TG molecule (PLnP) greatly enhanced the formation of the CFAM upon heating at temperatures below
240°C. On the other hand, 18:3n-3 in monoacid TG (LnLnLn) was highly resistant to CFAM formation within the same range of
temperatures (180–220°C). The TG structure, more than the TG composition, seemed to explain the differences in the CFAM formation
between the original canola oil and its interesterified counterpart. Like α-Ln, 18:2n-6 was more prone to cyclization when
attached at the central position of the model TG. Conversely, the influence of the TG composition on the cyclization rate
was less important for L than for α-Ln. It was concluded that positioning the C18 polyunsaturated fatty acid in the central
position of TG rendered the oils much more sensitive to the cyclization reaction upon heat treatment. 相似文献
8.
Natural refining of extruded-expelled soybean oils having various fatty acid compositions 总被引:2,自引:0,他引:2
Simple, low-capital-investment oil refining techniques, which may also meet the needs of natural or organic food industries, were explored to process extruded-expelled (E-E) soybean oils with various fatty acid compositions. Most settled E-E oils are naturally low in phosphatides (<100 ppm phosphorus) and were easily water degummed to low phosphorus levels (<55 ppm). Free fatty acids were reduced to 0.04% by adsorption with 3% Magnesol®. Magnesol reduced residual phosphorus contents to negligible levels. This material also adsorbed primary and secondary oil oxidation products. Our adsorption refining procedure was much milder than conventional refining, as indicated by little formation of primary and secondary lipid oxidation products and less loss of tocopherol. The remaining challenge to effective natural refining is the removal of off-flavor components. Our adsorption treatment reduced the natural flavor of soybean oil but flavor was still present, probably too strong for many consumers. Polyunsaturated oils oxidized more easily than did the other types of oils; therefore, precautions should be taken when refining such oils. High-oleic soybean oil, on the other hand, had excellent oxidative stability and better flavor characteristics after degumming and adsorption with Magnesol compared with other oils. 相似文献
9.
Hervé C. Gérard Robert A. Moreau William F. Fett Stanley F. Osman 《Journal of the American Oil Chemists' Society》1992,69(4):301-304
A new high-performance liquid chromatography technique with an evaporative light-scattering detector (ELSD) has been developed
for the separation and quantitative analysis of hydroxy and epoxy fatty acids. This method employs a gradual binary gradient
(hexane/isopropanol) and ELSD detection. The minimum limit of detection is about 1 μg and ratio of mass to signal is essentially
linear in the range of 10 to 200 μg. This high-performance liquid chromatography (HPLC) technique is able to separate various
positional isomers of mono-hydroxy and dihydroxy fatty acids and can also discriminate between monohydroxy, epoxy, epoxyhydroxy,
dihydroxy and trihydroxy fatty acids. 相似文献
10.
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
11.
Marek Gogolewski Malgorzata Nogala‐Kalucka Mariusz Szeliga 《European Journal of Lipid Science and Technology》2000,102(10):618-623
Among the most important metabolic compounds there are some which are not synthesized by human and animal organisms and have to be supplied in appropriate quantities in due time. Vitamin E and the essential unsaturated fatty acids have crucial physiological significance, and their greatest quantities occur in plant oils. During refining, apart from unnecessary substances, nutritionally advantageous compounds are also being eliminated. In the present paper changes of tocochromanols taking place during refining of rapeseed oil obtained from seeds of two subsequent crops were investigated. It was observed that losses of tocopherols exceeded 30%, two thirds of which resulted from distilling off during deodorization. The ratio of vitamin E to essential unsaturated fatty acids expressed as the Harris coefficient decreased in the refined oil obtained from seeds of two subsequent crops by about 28%. 相似文献
12.
Whole soybeans were exposed to microwave roasting for 6, 12, and 20 min at a frequency of 2,450 MHz and were studied not only
for phospholipid composition but also for positional distribution of the fatty acids. During microwave roasting, the greatest
rate of phospholipid losses (P<0.05) was observed in phosphatidylethanolamine (PE), followed by phosphatidylcholine (PC) and phosphatidylinositol (PI),
respectively. Therefore, the effects of microwave roasting on the composition and positional distribution of the fatty acids
are likely clearer in PE than in PC or PI. However, the principal characteristics for the positional distribution of fatty
acids are still retained during microwave roasting: unsaturated fatty acids, especially linoleic, are predominantly concentrated
in the 2-position, and saturated fatty acids, especially palmitic, primarily occupy the 1-position after 12 or 20 min of roasting.
The results suggest that unsaturated fatty acids located in the 2-position are significantly protected from microwave roasting. 相似文献
13.
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
14.
Jeongmok Kim Yangsoon Lee Sean F. O’Keefe Cheng-i Wei 《Journal of the American Oil Chemists' Society》1997,74(5):539-542
Chlorine dioxide (CIO2) has been explored as a potential substitute for aqueous chlorine to clean seafood products. In an attempt to understand
the interaction of CIO2 with organic compounds, duplicate fillets of Atlantic salmon (Salmo salar) and red grouper (Epinephelus morio) were treated for 5 min with freshly prepared aqueous CIO2 at 20, 40, 100, and 200 ppm total available CIO2 in 3.5% brine. Thiobarbituric acid (TBA) values and fatty acid composition were determined. CIO2-treated salmon and red grouper showed a dose-related increase in TBA; the 100 and 200 ppm groups had significantly (P<0.05) greater TBA values than controls and the 20 ppm group. Treated red grouper and salmon did not differ in percentage
monounsaturated and polyunsaturated fatty acids compared to controls, although differences occurred with some individual fatty
acids. Thus, CIO2 treatment did not greatly affect fatty acid composition of treated fillets. 相似文献
15.
Helen L. Ngo Eunha Hoh Thomas A. Foglia 《European Journal of Lipid Science and Technology》2012,114(2):213-221
The development of viable technologies for producing green products from renewable fats and oils is highly desirable since such materials can serve as replacements for non‐renewable and poorly biodegradable petroleum‐based products. Mixtures of saturated branched‐chain fatty acid isomers (sbc‐FAs), commonly referred to as isostearic acid, are important intermediates for the production of biodegradable lubricants, cosmetics, emollients, and hydraulic fluids. Present methods for producing sbc‐FAs, however, often give low yields of sbc‐FAs or sbc‐FA preparations with a high content of dimer acid fatty acid co‐products. This study reports an improved route to synthesizing sbc‐FAs from monounsaturated fatty acids using a modified H‐Ferrierite zeolite catalyst in conjunction with small amounts of triphenylphosphine additive. The yields of sbc‐FAs (up to 80 wt%) and co‐products (up to15 wt%) were determined using a modification of a previously reported GC method. A more detailed analysis of the distribution of sbc‐FA isomers in the products was made by the combined use of GC × GC‐TOF‐MS. Additionally, it was found that the H‐Ferrierite zeolite catalyst was recyclable and reusable up to 10 times without significant loss of activity and selectivity for sbc‐FAs. 相似文献
16.
脂肪酸类相变材料传热及液相渗漏的研究进展 总被引:2,自引:0,他引:2
能源的大量消耗使得储热技术研究越来越重要,相变材料作为一种有效的潜热储热材料在潜热储热系统中占据重要地位。脂肪酸相变材料因其来源广泛,具有共熔和共结晶特点、相变焓高和清洁可再生等优点受到广泛关注,但脂肪酸相变材料也存在热导率低和固-液相转变时液相渗漏等缺点。本文对国内外脂肪酸相变材料的传热和渗漏进行了综述与讨论,就热导率低的缺点提出了强化传热的方式,通过建立传热模型研究其导热行为并预测传热系数;就渗漏问题提出4种有效解决液相渗漏的方法,分析了各种方法的优缺点。对节能环保要求越来越高的今天,解决脂肪酸相变材料的传热和渗漏已成为热点问题。最后对脂肪酸相变材料的发展前景进行展望。 相似文献
17.
P. Kashulines S. S. H. Rizvil P. Harriott J. A. Zollweg 《Journal of the American Oil Chemists' Society》1991,68(12):912-921
The viscosities of several types of lipids saturated with supercritical carbon dioxide (SC-CO2) were measured with a high-pressure capillary viscometer. Oleic acid and linoleic acid were evaluated from 85 to 350 bar
at 40 and 60°C. The more SC-CO2-soluble methylated derivatives of these fatty acids were evaluated from 90 to 170 bar at 40 and 60°C. The complex mixture
of anhydrous milk fat (AMF) was evaluated from 100–310 bar at 40°C. The viscosities of the methylated fatty acids saturated
with SC-CO2 decreased between 5 and 10 times when the pressure increased from 1 to 80 bar, followed by a further decrease by a factor
of 2 to 3 when the pressure was increased from 80 to 180 bar. The viscosities of the fatty acids and AMF saturated with SC-CO2 had viscosity reduction similar to the methylated fatty acids between 1 and 80 bar, but they decreased much less between
80 and 350 bar. At constant pressure, the viscosity of the fatty acids and AMF decreased with increasing temperature, whereas
the viscosity of the methylated fatty acids increased with increasing temperature. The lipid/SC-CO2 mixtures were Newtonian, and their viscosities were best interpreted by using the mass concentration of dissolved SC-CO2 in the lipids and the pure component viscosities. 相似文献
18.
The oil content and fatty acid composition of commercially important Turkish fish species (anchovy,Engraulis encrasicholus; freshwater rainbow trout,Salmo gairdneri; and cultured salmon,S. salar) were determined. Palmitic (16∶0), palmitoleic (16∶1), oleic (18∶1), and docosahexaenoic (22∶6) acids were the most abundant
fatty acids in all species. Eicosapentaenoic acid (20∶5) was twice as high in the anchovy oil as in the rainbow trout and
salmon oils. Significant quantities of linoleic acid (18∶2) and docosahexaenoic acids (22∶6) were found in both rainbow trout
and salmon samples. The individual fatty acid data obtained from rainbow trout and salmon were similar to each other. All
three fish species contain high levels of n-3 polyunsaturated fatty acids and would be suitable for inclusion in the formulation
of low-fat highly unsaturated diets. 相似文献
19.
Soybean lecithin is used as an emulsifier in food, cosmetic, and pharmaceutical industries. The proportion of individual phospholipids
(PL) and their FA composition may affect the functional properties of lecithin. In this research, lecithins recovered from
four modified soybeans and one commodity soybean, which were processed by extrusion-expelling and conventional solvent extraction,
were analyzed for proportion of PL class and FA composition. HPLC with an ELSD analysis demonstrated that the percentage of
PC in extrusion-expelled lecithin was higher than in solvent-extracted lecithin, whereas the PE content was lower. GC analysis
showed that FA compositions of the PL varied with soybean type. The oil extraction method did not significantly affect FA
composition. Critical micelle concentration tested with a tensiometer showed differences among the lecithins. 相似文献
20.
Lars Ovesen Torben Leth Kirsten Hansen 《Journal of the American Oil Chemists' Society》1998,75(9):1079-1083
This study examined trans monounsaturated fatty acid contents in all margarines and shortenings marketed in Denmark, and in frying fats used by the
fast-food restaurants Burger King and McDonald’s. Trans C18:1 content was 4.1±3.8% (g per 100 g fatty acids) in hard margarines, significantly higher than the content in soft margarines
of 0.4±0.8%. Shortenings had an even higher content of trans C18:1, 6.7±2.3%, than the hard margarines. Margarines and shortenings with high contents of long-chain fatty acids had about 20%
total trans monoenoic of which close to 50% were made up of trans long-chain fatty acids. Both fast-food frying fats contained large amounts of trans C18:1, 21.9±2.9% in Burger King and 16.6±0.4% in McDonald’s. In Denmark the per capita supply of trans C18:1 from margarines and shortenings and frying fats has decreased steadily during recent years. The supply of trans C18:1 from margarines and shortenings in the Danish diet is now 1.1 g per day. 相似文献