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1.
A series of plastic fats containing no trans FA and having varying melting or plastic ranges, suitable for use in bakery, margarines, and for cooking purposes as vanaspati,
were prepared from palm oil. The process of fractionating palm oil under different conditions by dry and solvent fractionation
processes produced stearins of different yields. Melting characteristics of stearin fractions varied depending on the yield
and the process. The lower-yield stearins were harder and had a wider plastic range than those of higher yields. The fractions
with yields of about 35% had melting profiles similar to those of commercial vanaspati. The plastic range of palm stearins
was further improved by blending them with corresponding oleins and with other vegetable oils. The plasticity or solid fat
content varied depending on the proportion of stearin. Blends with higher proportions of stearins were harder than those with
lower proportions. the melting profiles of some blends, especially those containing 40–60% stearin of about 25% yield and
40–60% corresponding oleins or mahua or rice bran oils, were similar to those of commercial vanaspati and bakery shortenings.
These formulations did not contain any trans FA, unlike those of commercial hydrogenated fats. Thus, by fractionation and blending, plastic fats with no trans acids could be prepared for different purposes to replace hydrogenated fats, and palm oil could be utilized to the maximum
extent. 相似文献
2.
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
3.
Lars Ovesen Torben Leth Kirsten Hansen 《Journal of the American Oil Chemists' Society》1998,75(12):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
4.
Sakina Khatoon Sunki Reddy Yella Reddy 《European Journal of Lipid Science and Technology》2005,107(11):786-791
Speciality plastic fats with no trans fatty acids suitable for use in bakery and as vanaspati are prepared by interesterification of blends of palm hard fraction (PSt) with mahua and mango fats at various proportions. It was found that the interesterified samples did not show significant differences in solid fat content (SFC) after 0.5 or 1 h reaction time. The blends containing PSt/mahua (1:1) showed three distinct endotherms, indicating a heterogeneity of triacylglycerols (TG), the proportions of which altered after interesterification. The SFC also showed improved plasticity after interesterification. Similar results were observed with other blends of PSt/mahua (1:2). These changes in melting behavior are due to alterations in TG composition, as the trisaturated‐type TG were reduced and the low‐melting TG increased after interesterification. The blends containing PSt/mango (1:1) showed improvement in plasticity after interesterification, whereas those containing PSt/mango (2:1) were hard and showed high solid contents at higher temperature and hence may not be suitable for bakery or as vanaspati. The blends with palm and mahua oils were softer and may be suitable for margarine‐type products. The results showed that the blends of PSt/mahua (1:1, 1:2) and PSt/mango (1:1) after interesterification for 1 h at 80 °C showed an SFC similar to those of commercial hydrogenated bakery shortenings and vanaspati. Hence, they could be used in these applications in place of hydrogenated fats as they are free from trans acids, which are reported to be risk factors involved in coronary heart disease. For softer consistency like margarine applications, the blends containing palm oil and mahua oil are suitable. 相似文献
5.
Physical and chemical properties of trans-free fats produced by chemical interesterification of vegetable oil blends 总被引:1,自引:0,他引:1
V. Petrauskaite W. De Greyt M. Kellens A. Huyghebaert 《Journal of the American Oil Chemists' Society》1998,75(4):489-493
Fat blends, formulated by mixing a highly saturated fat (palm stearin or fully hydrogenated soybean oil) with a native vegetable
oil (soybean oil) in different ratios from 10:90 to 75:25 (wt%), were subjected to chemical interesterification reactions
on laboratory scale (0.2% sodium methoxide catalyst, time=90 min, temperature=90°C). Starting and interesterified blends were
investigated for triglyceride composition, solid fat content, free fatty acid content, and trans fatty acid (TFA) levels. Obtained values were compared to those of low- and high-trans commercial food fats. The interesterified blends with 30–50% of hard stock had plasticity curves in the range of commercial
shortenings and stick-type margarines, while interesterified blends with 20% hard stock were suitable for use in soft tubtype
margarines. Confectionery fat basestocks could be prepared from interesterified fat blends with 40% palm stearin or 25% fully
hydrogenated soybean oil. TFA levels of interesterified blends were low (0.1%) compared to 1.3–12.1% in commercial food fats.
Presented at the 88th AOCS Annual Meeting and Expo, May 11–14, 1997, Seattle, Washington. 相似文献
6.
Corinne C. Bayard Robert L. Wolff 《Journal of the American Oil Chemists' Society》1995,72(12):1485-1489
The fatty acid composition of twelve French tub margarines and three industrial shortenings was established with particular
attention to theirtrans-18:1 acid content. Four of the twelve margarines (including two major brands, with 60% of market share) were devoid oftrans isomers, one contained less than 2%trans-18:1 acids, whereas the seven others had a mean content of 13.5 ± 3.6%trans isomers. Four years ago, no margarines with 0%trans-18:1 acids could be found. It is deduced that the recent Dutch and American studies on possible effects oftrans acids on human health (serum cholesterol, heart disease risks) may have had some influence on French margarine manufacturers.
Presently, an average French tub margarine contains only 3.8% oftrans-18:1 acids instead of 13% four years ago. To protect brand names, some manufacturers have replaced partially hydrogenated
oils with tropical fats or fully hydrogenated oils. On the other hand, two of the three shortenings had high levels oftrans-18:1 acids: 53.5 and 62.5%. This last value, obtained for a sample of hydrogenated arachis oil, seems to be one of the highest
values ever reported for edible hydrogenated oils. In this sample,trans-18:1 plus saturated acids accounted for 85% of total fatty acids. This would indicate that shortening producers and users
are not yet aware of recent dietary recommendations, probably because these products are not easily identifiable by consumers
in food items, in contrast to margarines. 相似文献
7.
A Fourier transform infrared spectroscopic procedure was used to analyze 34 edible fats (22 shortenings and 12 vegetable margarines)
as neat fats (IRNF) to determine their total trans fatty acid (TFA) content. The sloping baseline was corrected with a reference spectrum based on a nonprocessed olive oil.
The calibration was done using seven partially hydrogenated fats with an individual TFA content previously determined by the
combination of gas chromatography (GC) with argentation thin-layer chromatography. Taking into account the different absorptivities
of various trans isomers, different correction factors were calculated using the calibration standards (0.83 and 1.71 for single trans bonds in both diethylene and triethylene and for trans, trans-diethylene fatty acids, respectively) and applied to calculate the total TFA of samples. Moreover, the samples were converted
to their methyl esters and reanalyzed following the same procedure (IRFAME). Differences in TFA content of fats were not found when a t-test was used to compare the results obtained by IRNF vs. either IRFAME or GC, suggesting that IR of neat fats could be used, thus avoiding the need to prepare sample solutions in organic solvents
and to prepare fatty acid methyl esters. The mean TFA content (determined by IRNF) of a representative group of Spanish shortenings (22 samples) that varied widely in terms of fat sources, processes, and
purposes (bakery, sandwiches, ice cream, coatings, chocolate coverings) was 6.55±11.40%, although more than 54% contained
<3% of TFA. Fatty acid composition of shortenings by direct GC using a 100-m polar cyanopolysiloxane capillary column indicated
that the mean trans-18∶2 isomer content was 0.58%, ranging from 0.9 to 3.4%. Small amounts of trans-18∶3 isomers (<0.3%) were observed in 18 of the 22 shortenings studied; the maximal value was <2%. The mean value of the
fraction saturated+TFA of shortenings was high (59.95±12.73%), including two values higher than 83%. 相似文献
8.
The fruit of the oil palm yields two types of oil. The flesh yields 20–22% of palm oil (C16∶0 44%, C18∶1 39%, C18∶2 10%).
This represents about 90% of the total oil yield. The other 10%, obtained from the kernel, is a lauric acid oil similar to
coconut oil. Palm oil is semisolid, and a large part of the annual Malaysian production of about 14 million tonnes is fractionated
to give palm olein, which is widely used for industrial frying, and palm stearin, a valuable hard stock. Various grades of
the latter are available. Formulae have been developed by straight blending and by interesterification of palm oil and palm
kernel oil to produce shortenings and margarines using hydrogenated fats to give the consistency required. Products that include
these formulations are cake shortenings, vanaspati (for the Indian subcontinent), soft and brick margarines, pastry margarines,
and reduced fat spreads. Other food uses of palm products in vegetable-fat ice cream and cheese, salad oils, as a peanut butter
stabilizer, and in confectioners fats are discussed briefly here. 相似文献
9.
Margarines and shortenings have been major contributors to the intake by humans of the probably atherogenic trans FA (TFA). In 1999, all 73 brands of margarines and shortenings on the Danish market were analyzed by GLC on a 50-m highly
polar capillary column, and the results were compared with similar investigations in 1992 and 1995. A gradual decline of TFA
in Danish margarines was observed. From 1992 to 1995, a reduction of TFA from 10.4 to 3.6% took place in margarines with 20–40%
linoleic acid. In 1999, TFA was practically absent in all the margarines, but it remained unchanged in shortenings, averaging
about 6–7%. Long-chain TFA from hydrogenated fish oil, although present in 13 brands in 1995, were not found at all in the
1999 samples. Trans-linoleic acids or CLA were not found. The reduction in TFA content in margarines has not resulted in a systematic change
over the years in the content of saturated FA, monounsaturated FA, or PUFA. Calculated from sales figures, the intake of TFA
decreased from 2.2 g per capita per year in 1992, to 1.5 g in 1995, and to 0.4 g in 1999. 相似文献
10.
A rapid method for analysis of trans and cis FA in hydrogenated fats has been developed. The method is based on a single anlaysis by CG with IR detection. Multivariate
partial least squares regression is applied on the IR spectra to predict the number of cis and trans double bonds. For each chain length the method provides information about the amount of the saturated FA, the amount of trans monoenes, the amount of cis monoenes, the amount of PUFA, and the average number of cis and trans double bonds in PUFA. The method has been validated by summing the values to a total trans value and total unsaturation. These sum values were compared with total trans unsaturation, as determined by AOCS method Cd 14-95, and iodine value, as determined by AOCS Cd 1d-92. 相似文献
11.
Frank D. Gunstone 《Journal of the American Oil Chemists' Society》1993,70(10):965-970
The high-resolution13C nuclear magnetic resonance spectra of twelve hydrogenated fats have been examined. Each spectrum contains 50–100 signals
and reveals much about the nature of the acyl chains of both double-bond position and configuration. The signals for the ω1,
ω2 and ω3 carbon atoms give information on thecis andtrans isomers of the Δ15, Δ14, Δ13 and Δ12 18:1 esters, respectively. Allylic signals distinguish betweencis andtrans esters, and the proportion of totalcis to totaltrans isomers can be obtained from these. Olefinic signals are the most informative, and most of these have been assigned. This
leads to a semi-quantitative estimate of the various 18:1 isomers present. Assignments are based mainly on information already
in the literature, but some were confirmed after urea fractionation of the acids from a hydrogenated oil in whichcis andtrans monoene acids were separately concentrated. 相似文献
12.
W. M. Nimal Ratnayake Steven L. Hansen Michael P. Kennedy 《Journal of the American Oil Chemists' Society》2006,83(6):475-488
The AOCS Official Method Ce 1h-05 was recently approved at the 96th AOCS Annual Meeting (2005) by the Uniform Methods Committee
as the official method for determining cis and trans FA in vegetable or non-ruminant fats and oils. A series of experiments was undertaken using a margarine (hydrogenated soybean
oil) sample containing approximately 34% total trans FA (28% 18∶1 trans, 6% 18∶2 trans, and 0.2% 18∶3 trans), a low-trans oil (ca. 7% total trans FA), and a proposed system suitability mixture (12∶0, 9c−18∶1, 11c−18;1, 9c,12c,15c−18∶3, 11c−20∶1, and 21∶0) in an effort to evaluate and optimize the separation on the 100-m SP-2560 and CP-Sil 88 flexible fused-silica
capillary GC columns recommended for the analysis. Different carrier gases and flow rates were used during the evaluation,
which eventually lead to the final conditions to be used for AOCS Official Method Ce 1h-05. 相似文献
13.
This study presents the FA composition and trans FA (TFA) contents of different hydrogenated vegetable oils and blended fats marketed in Pakistan. Thirty-four vanaspati (vegetable
ghee), 11 shortenings, and 11 margarines were analyzed. The contents of saturated FA, cis monounsaturated FA, and cis PUFA were in the following ranges: vanaspati 27.8–49.5, 22.2–27.5, 9.3–13.1%; vegetable shortenings 37.1–55.5, 15.8–36.0,
2.7–7.0%; and margarines 44.2–55.8, 21.7–39.9, 2.9–20.5%, respectively. Results showed significantly higher amounts of TFA
in vanaspati samples, from 14.2 to 34.3%. Shortenings contained TFA proportions of 7.3–31.7%. The contents of TFA in hard-type
margarines were in the range of 1.6–23.1%, whereas soft margarines contained less than 4.1% TFA. 相似文献
14.
An infrared spectrophotometric procedure, based on the fatty acid methyl ester mixture derived from a partially hydrogenated
vegetable oil as the calibration standard, has been developed for accurate analysis of the totaltrans content of hydrogenated fats. This procedure produces more accurate results than the current official methods of Association
of Official Analytical Chemists and American Oil Chemists’ Society, both of which use methyl elaidate as the external standard.
The results obtained with this procedure were in close agreement to those determined by the combined procedure of silver-nitrate
thin-layer chromatography and capillary gas-liquid chromatography. The improved results, obtained with the partially hydrogenated
vegetable oil methyl esters as the calibration standard, may be attributable to its assortment oftrans isomers, which may have different absorptivities relative to methyl elaidate. 相似文献
15.
F. R. van de Voort A. A. Ismail J. Sedman G. Emo 《Journal of the American Oil Chemists' Society》1994,71(3):243-253
Edible fats and oils in their neat form are ideal candidates for Fourier transform infrared (FTIR) analysis, in either the
attenuated total reflectance or the transmission mode. FTIR spectroscopy provides a simple and rapid means of following complex
changes that take place as lipids oxidize. Safflower and cottonseed oils were oxidized under various conditions, and their
spectral changes were recorded and interpreted. The critical absorption bands associated with common oxidation end products
were identified by relating them to those of spectroscopically representative reference compounds. The power and utilty of
FTIR spectroscopy to follow oxidative changes was demonstrated through the use of “real-time oxidation plots.” A quantitative
approach is proposed in which standards are used that are spectroscopically representative of oxidative end products and by
which the oxidative state of an oil can be defined in terms of percent hydroperoxides, percent alcohols and total carbonyl
content. By using either relative absorption as a basis or calibrating on representative standards, FTIR analysis provides
a rapid means of evaluating the oxidative state of an oil or of monitoring changes in oils undergoing thermal stress. 相似文献
16.
Two gas chromatography (GC) procedures were compared for routine analysis of trans fatty acids (TFA) of vegetable margarines, one direct with a 100-m high-polarity column and the other using argentation thin-layer
chromatography and GC. There was no difference (P>0.05) in the total trans 18∶1 percentage of margarines with a medium level of TFA (∼18%) made using either of the procedures. Both methods offer good
repeatability for determination of total trans 18∶1 percentage. The recoveries of total trans isomers of 18∶1 were not influenced (P>0.1) by the method used. Fatty acid composition of 12 Spanish margarines was determined by the direct GC method. The total
contents of trans isomers of oleic, linoleic, and linolenic acids ranged from 0.15 to 20.21, from 0.24 to 0.99, and from 0 to 0.47%, respectively,
and the mean values were 8.18, 0.49, and 0.21%. The mean values for the ratios [cis-polyunsaturated/(saturated +TFA)] and [(cis-polyunsaturated + cis-monounsaturated)/(saturated +TFA)] were 1.25±0.39 and 1.92±0.43, respectively. Taking into account the annual per capita
consumption of vegetable margarine, the mean fat content of the margarines (63.5%), and the mean total TFA content (8.87%),
the daily per capita consumption of TFA from vegetable margarines by Spaniards was estimated at about 0.2 g/person/d. 相似文献
17.
Lard and high-oleic sunflower oil (Trisun® Extra) were interesterified at 55°C for 24 h with SP435 lipase from Candida antarctica to produce plastic fats. As the amount of trisun increased, percentage free fatty acid, unsaturated fatty acid/saturated fatty acid value, oxidizability, and the amount of 18:1 found at the sn-2 position of triglyceride products increased. Differential scanning calorimetry showed that the low-melting components in the product contained more 18:1 than the high-melting components. A 60:40 (w/w) ratio of lard to trisun had the widest plastic range (3–26°C). The scaled-up reaction to produce this blend resulted in a product that had 60.1% 18:1 at the sn-2 position compared to 44.9% for the physical blend. The solid fat content of the 60:40 interesterified mixture resembled soft-type margarine oil. 相似文献
18.
J. Sedman F. R. van de Voort A. A. Ismail 《Journal of the American Oil Chemists' Society》1997,74(8):907-913
An automated protocol for the direct, rapid determination of isolated trans content of neat fats and oils by Fourier transform infrared (FTIR) spectroscopy was devised, based on a simple modification
of the standard AOCS trans method, eliminating the use of CS2 and methylation of low trans samples. Through the use of a commercially available, heated transmission flow cell, designed specifically for the analysis
of neat fats and oils, a calibration (0–50%) was devised with trielaidin spiked into a certified, trans-free soybean oil. The single-beam spectra of the calibration standards were ratioed against the single-beam spectrum of the
base oil, eliminating the spectral interference caused by underlying triglyceride absorptions, facilitating direct peak height
measurements as per the AOCS IR trans method. The spectrometer was preprogrammed in Visual Basic to carry out all spectral manipulations, measurements, and calculations
to produce trans results directly as well as to provide the operator with a simple interface to work from. The derived calibration was incorporated
into the software package, obviating the need for further calibration because the program includes an automatic recalibration/standardization
routine that automatically compensates for differences in optical characteristics between instruments, instrument drift over
time, and cell wear. The modified AOCS FTIR analytical package was evaluated with Smalley check samples for repeatability,
reproducibility, and accuracy, producing SD of ± 0.07, 0.13, and 0.70 trans, respectively, the FTIR predictions being linearly related to the Smalley means (r=0.999; SD=± 0.46), and well within one SD of the Smalley sample means. Calibration transfer was assessed by implementing
the calibration on a second instrument and reanalyzing the Smalley check samples in cells of two different pathlengths (25-
and 50-μm). There were no statistically significant differences between the FTIR trans predictions obtained for the Smalley samples from the two instruments and two cells, indicating that the software was able
to adjust the calibrations to compensate for differences in instrument response and cell pathlength. The FTIR isolated trans analysis protocol developed by the McGill IR Group has the benefit of being based on the principles of an AOCS-approved method,
matches its accuracy, and allows the analysis to be performed on both neat fats and oils, producing trans predictions in less than 2 min per sample. It is suggested that this integrated approach to trans analysis, which requires a minimum level of sample manipulation and operator skill, be considered as a modification of the
proposed Recommended Practice CD14b-95. 相似文献
19.
Several pilot-scale trials reported in this paper, using palm stearin-rice bran oil (PS-RBO) blends, obviously did not contain
trans FA (TFA), whereas the commercial products were found to contain 18–27% TFA. The effects of processing conditions such as
rate of agitation, crystallization temperature, and composition of the blends on the crystal structure of shortenings were
studied. The products were evaluated for their physicochemical characteristics using DSC, X-ray diffraction (XRD), HPLC, and
FTIR techniques. The formulation containing 50% PS and 50% RBO showed melting and cooling characteristics similar to those
of hydrogenated commercial “vanaspati” samples. Analysis of the FA composition revealed that the formulated shortenings contained
15–19% C18∶2 PUFA. Tocopherol and tocotrienol contents of the experimental shortenings were in the range of 850–1000 ppm with oryzanol
content up to 0.6%. XRD studies demonstrated that the crystal form in the shortenings was predominantly the most stable β′
form, and there was less of the undesirable β form. 相似文献
20.
Matthew J. Hills Irmgard Kiewitt Kumar D. Mukherjee 《Journal of the American Oil Chemists' Society》1990,67(9):561-564
Immobilized lipase preparations from seedlings of rape (Brassica napus L.) andMucor miehei (lipozyme) used as biocatalysts in esterification and hydrolysis reactions discriminate strongly against γ-linolenic and
docosahexaenoic acids/acyl moieties. Utilizing this property, γ-linolenic acid contained in fatty acids of evening primrose
oil has been enriched seven to nine-fold, from 9.5 to almost 85% by selective esterification of the other fatty acids with
butanol. Similarly, docosahexaenoic acid of cod liver oil has been enriched four to five-fold, from 9.4 to 45% by selective
esterification of fatty acids (other than docosahexaenoic acid) with butanol. As long as the reaction is stopped before reaching
equilibrium, very little of either γ-linolenic acid or docosahexaenoic acid are converted to butyl esters, which results in
high yields of these acids in the unesterified fatty acid fraction. 相似文献