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1.
The amount of trans fatty acids (TFA) in fourteen industrially hydrogenated and deodorized oils was determined. To achieve better sensitivity 200 μm KCl cell was used in transmission Fourier transform infrared (FT-IR) spectroscopy. The results of transmission FT-IR spectroscopy were evaluated by gas chromatography (GC) with flame ionization detector (FID), and found to be comparable. All analyzed cooking oil samples had a lower trans content of 0.4–1.8%. Trans fatty acid contents of partially hydrogenated oil samples were relatively higher as comparable to those of the cooking oils. Among the samples examined, the highest level was found to be at 26.5% and 25.7% by the GC–FID and FT-IR spectroscopy, respectively. Due to harmful effects, high amounts of trans fatty acids in partially hydrogenated oils is an alarming issue for the consumer’s health and quality control authorities.  相似文献   

2.
In this study a validated procedure for accurate determination of fatty acids in dairy products, with special emphasis on total trans fatty acids (TFA) content is presented. Dairy fat naturally contains 4–6% of trans fatty acids, mainly trans-octadecenoic acids (i.e. vaccenic acid), and 0.3–1.5% of conjugated linoleic acids (CLA). The proposed procedure does not require lipid extraction, and transesterification of lipids could be carried out directly on dairy products. Optimal analytical conditions have been developed to allow accurate determination of TFA content without prior fractionation of cis/trans FAME isomers by thin-layer chromatography. The methodology requires the use of a highly polar open tubular capillary column having at least 100 m length. CLA and other fatty acids from C4:0 (butyric) acid to long-chain polyunsaturated fatty acids (LC-PUFAs) could also be analyzed. Therefore, the methodology presented is versatile and could be used for both targeted analysis (e.g. determination of TFA in dairy products) and determination of the broad fatty acid profile in dairy products.  相似文献   

3.
4.
Silver ion solid phase extraction (Ag+-SPE) followed by GC/EI–MS operated in the selected ion monitoring (SIM) mode was used for the thorough analysis and comparison of fatty acids from bulk milk samples of farmed camel, moose, and cow along with one human milk sample. The GC/EI–MS–SIM mode took advantage of different time windows and enabled the unequivocal assignment of the number of double bonds. GC/MS was also used for structure verification. Ag+-SPE was of particular importance for the separation of cis- and trans-isomers. By the combination of both techniques we were able to determine the amounts of 29 saturated fatty acids (including up to eleven branched-chain fatty acids and the scarcely described 11-cyclohexylundecanoic acid which was detected in all samples), 16 cis- and 23 trans-monoenoic fatty acids as well as 19 polyunsaturated fatty acids including the conjugated linoleic acid (CLA) 18:2(9,11tr). Characteristic differences were observed in that human milk differed from the animal milks by its lower trans-fatty acid and branched-chain fatty acid content. In this set of samples, the branched-chain fatty acid content was highest in camel milk while moose milk contained the highest proportion of 18:1(9), 18:3(9,12,15), and 22:6(4,7,10,13,16,19). Although only one bulk sample was available for the animal milk the amounts determined fitted well with published data. Thus, this approach might be helpful to establish a more comprehensive data base for statistic evaluation.  相似文献   

5.
Effects on the fatty acid composition of cod (Gadus morhua) and salmon fillets (Salmo salar) after pan-frying in margarine and olive oil were determined. The fatty acids of the margarine used were 55.5% saturated (SFA), 33.0% mono-unsaturated (MUFA) and 11.5% polyunsaturated (PUFA). The olive oil used contained 15.4% SFA, 76.1% MUFA and 8.5% PUFA. Using margarine or olive oil increased the SFA and MUFA percentages, respectively, in both species. For cod fillets (lean), pan-frying increased the fat content (0.55–4.15 g/100 g and 0.55–2.30 g/100 g before and after pan-frying, with margarine and olive oil, respectively), whereas, for salmon fillets (fat), it decreased (13.91 to 10.57 g/100 g and 15.35 to 12.95 g/100 g before and after pan-frying with margarine and olive oil, respectively). In conclusion, the culinary fat selection affects the total fatty acid content and composition of the prepared fish fillet.  相似文献   

6.
In some countries the content oftransfatty acids (TFA) in margarines has strongly decreased as a result of the continuous discussion on their disadvantages regarding aspects of nutritional physiology. However, still in 1994 almost 1/3 of total fatty acids in part of German sunflower margarines, shortenings and cooking fats comprised these unfavourable TFA. In the present study the main interest was laid ontrans‐C16 : 1,trans‐C18 : 1,trans‐C20 : 1,trans‐C18 : 2 and trans‐C18 : 3 fatty acids and particularly their individual isomers, as negative metabolic activity of TFA possibly might only be attributable to certain isomers. By combining argentation thin‐layer chromatography with gas chromatography using a 100‐m capillary column (CP‐Sil 88) trans fatty acid contents were determined in nearly all German brands of sunflower margarines (SFM; n = 9) and of cooking fats and shortenings (CFS; n = 10). Concerning the above‐mentioned groups of isomers mean TFA contents of 0.01, 4.88, 0.00, 0.45 and 0.03% for SFM as well as of 0.01, 5.02, 0.03, 0.70 and 0.17% for CFS were established, respectively. The re‐evaluation of samples from 1994 and 1996 exhibited that the total TFA content (sum of all mentioned isomers) in SFM decreased from 21.77% (range: 13.78–26.29; n = 11) to 5.37% (1.98–6.15%; n = 9) between 1994 and 1999. Also the total TFA content in CFS on average strongly decreased from 11.77% (0.08–33.63; n = 16) in 1994 and 12.52% (1.61–26.79%; n = 7) in 1996 to 5.91% (0.43–19.72%; n = 10) in 1999. However, even the newest CFS samples partly exhibited relative high TFA contents. In addition to the total TFA contents all positional isomers of trans‐C18 : 1,trans‐C18 : 2 and trans‐C18 : 3 in SFM and CFS were quantified and compared between different years. The conjugated linoleic acid (cis Δ9,trans Δ11) occurred only in small amounts of 0.03% and 0.02% in current SFM and CFS.  相似文献   

7.
Levels of polyunsaturated fatty acids (PUFA), cis, cis-methylene interrupted polyunsaturated fatty acids (i.e. essential fatty acids—EFA) and isolated trans double bonds in six crude vegetable oils, seven commercial oils, eighteen margarines, two butter fats and fats from two types each of crisps and butter biscuits have been determined. The ratios between the PUFA or EFA and the saturated fatty acids of various samples have been tabulated. Normal (i.e. high linoleic) safflower seed oil gave the highest ratio. Margarines which were estimated to contain partially hydrogenated fish oils (45–90%, on fat basis) gave high values of trans double bonds. Butter fat having a similar EFA level to that present in a ‘hydrogenated fish oil’ margarine contained a much lower level of trans isomers. Almost all the PUFA in the oils of crips, and about half the PUFA content of butter biscuits, existed as ‘true’ essential fatty acids.  相似文献   

8.
In order to find out new sources of premium quality edible oil in the country, seeds of ten varieties of Sorghum bicolor were initially analyzed for their total oil contents. The seed oil was later fractionated into eight fatty acids including two new saturated fatty acids. The oil contents were determined by Soxhlet method and compared with the results obtained by NMR analysis. The total oil contents in the seeds of sorghum ranged from 5.0 to 8.2 % (w/w), indicating non significant difference obtained by two different techniques. The results revealed that oleic acid (31.12–48.99%), Palmitoleic acid (0.43–0.56%), linoleic acids (27.59–50.73%), linolenic acid (1.71–3.89%), stearic acid (1.09–2.59%) and palmitic acid (11.73–20.18%) was present in the seed oil of different sorghum varieties when analyzed by GC–MS. It was observed that in most of the varieties polyunsaturated fatty acids (PUFA) were higher than monounsaturated fatty acids (MUFA). The two atypical SFAs, octanedioic (C8:0) and azelaic acid (C9:0) were found in some varieties. These results suggest that these S. bicolor varieties could be additional sources of edible oil due to presence of clinically important saturated and high concentration of unsaturated fatty acids. A large scale production of the seed oil after refining process can contribute towards alleviation of edible oil shortage in the country with increased use of premium quality oil.  相似文献   

9.
Abstract: Omega‐3 fatty acids (n‐3 FAs) have been positively associated with prevention and treatment of chronic diseases. Intake of high amounts of trans fatty acids (TFAs) is correlated with increased risk of coronary heart disease, inflammation, and cancer. Structured lipid (SL) was synthesized using stearidonic acid (SDA) soybean oil and high‐stearate soybean oil catalyzed by Lipozyme® TLIM lipase. The SL was compared to extracted fat (EF) from a commercial brand for FA profile, sn‐2 positional FAs, triacylglycerol (TAG) profile, polymorphism, thermal behavior, oxidative stability, and solid fat content (SFC). Both SL and EF had similar saturated FA (about 31 mol%) and unsaturated FA (about 68 mol%), but SL had a much lower n‐6/n‐3 ratio (1.1) than EF (5.8). SL had 10.5 mol% SDA. After short‐path distillation, a loss of 53.9% was observed in the total tocopherol content of SL. The tocopherols were lost as free tocopherols. SL and EF had similar melting profile, β’ polymorph, and oxidative stability. Margarine was formulated using SL (SLM) and EF (RCM, reformulated commercial margarine). No sensory difference was observed between the 2 margarines. The SL synthesized in this study contained no TFA and possessed desirable polymorphism, thermal properties, and SFC for formulation of soft margarine. The margarine produced with this SL was trans‐free and SDA‐enriched. Practical Application: The current research increases the food applications of stearidonic acid (SDA) soybean oil. trans‐Free SDA containing SL was synthesized with desirable polymorph, thermal properties, and SFC for formulation of soft margarine. The margarine produced with this SL had no trans fat and had a low n‐6/n‐3 ratio. This may help in reducing trans fat intake in our diet while increasing n‐3 FA intake.  相似文献   

10.
The aim of the present study was to describe the dietary pattern of a representative sample of 516 adult participants (203 men and 313 women) from Catalonia, a Spanish Mediterranean region, to assess their current dietary and plasma levels of trans C18:1, the major trans-fatty acid (TFA), and cis-9, trans-11 CLA, and trans-10, cis-12 CLA, the two major conjugated linoleic acid (CLA) isomers, and to evaluate their correlation with several cardiovascular disease risk factors. The population was a random sample derived from the Catalan Nutrition Survey. Plasma levels of the CLA isomers were determined in a subsample of 100 volunteers. The Catalan diet seemed to maintain some traits of the ‘traditional’ Mediterranean diet, although other components were lost. The dietary intakes of saturated fatty acids (SFA), TFA, cis-9, trans-11 CLA, and trans-10, cis-12 CLA were 12.3%, 0.84% (2.0 g/d), 0.030% (71.5 mg/d), and 0.0015% (3.4 mg/d) of the energy intake, respectively. Trans C18:1 accounted for 0.19% of the total plasma fatty acids, while the sum of cis-9, trans-11and trans-10, cis-12 CLA isomers represented about 0.09% of the plasma fatty acids. Trans C18:1 isomers correlated significantly with the intake of French fries and pastries, while cis-9, trans-11 CLA significantly correlated with the intake of dairy products and ruminant meat. None of the cardiovascular disease risk factors were found to be associated with the plasma levels of TFA or CLA. The results of this study suggest that monounsaturated fatty acids (MUFA) are the main dietary fat source in the Catalan population, due to their regular olive oil consumption. Moreover, plasma levels of the main TFA and CLA suggest that the Catalan diet is not at present strongly influenced by the occidental dietary patterns. However, a reduction of the intake of SFA in the Catalan population should be recommended.  相似文献   

11.
Fourier transform infrared spectroscopy (FTIR) with horizontal attenuated total reflectance (HATR) coupled to multivariate analysis was used to predict chemical composition, fatty acid profile, nutritional relationships between fatty acids, and to identify trans fatty acids (TFA) of margarines. For model building and validation, a set of 42 margarines samples were analyzed in terms of fatty acid profile, total fat, moisture, and salt content. The quantitative models were based on incorporating the above chemical parameters of the different margarines and HATR-FTIR spectral information into the calibration model using chemometric analysis. Chemical parameters for total fat, moisture, and salt content ranged 39–84.5%, 14.5–59%, and 0.3–2.6%, respectively. Regarding fatty acids, the concentration of TFA, saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), and polyunsaturated fatty acid (PUFA) ranged 0–34.06%, 17.17–54.20%, 15.26–34.49%, and 4.02–53.89% (g/100 g margarine), respectively. Principal components regression (PCR) and partial least square analysis (PLS) were used to inspect the variation within the sample set. The best model to predict the chemical composition was obtained using the algorithm partial least squares (PLS) with a R 2 greater than 0.933 and SEC and SEP less than 1.294 and 1.406, respectively. The optimized SIMCA model used to identify high or low TFA content showed 100% correct classification rate of both margarines with less than 2.0 g TFA/100 g fat as more than 2.0 g TFA/100 g fat. Compared with traditional chemical analysis, the FTIR-HATR models analyzed margarines in minutes and directly in their neat form.  相似文献   

12.
Fatty acid distribution of triacylglycerols (TAG) and phospholipids (PL) obtained from the four cultivars of broad beans (Vicia faba) was investigated. Total lipids extracted from the beans were separated by thin-layer chromatography into eight fractions. The major lipid components were TAG (47.7–50.1%) and PL (47.5–50.5%), while hydrocarbons, steryl esters, free fatty acids, diacylglycerols (1,3-DAG and 1,2-DAG) and monoacylglycerols were present in minor proportions (1.8–2.4%). The major PL components were phosphatidylcholine (56.4–58.4%), phosphatidylethanolamine (20.3–21.7%) and phosphatidylinositol (16.6–18.6%). Phosphatidylinositol was unique in that it had the highest saturated fatty acid content among the three PL. No significant differences (P > 0.05) in fatty acid distribution existed when the different cultivars were compared. The fatty acid distributions in the TAG were evident among the four cultivars: unsaturated fatty acids were predominantly concentrated in the sn−2 position, and saturated fatty acids primarily occupied the sn−1 or sn−3 position in the oils. These results could be useful to both consumers and producers for manufacture of traditional foods in Japan and elsewhere.  相似文献   

13.
Seasonal variations on total fatty acid compositions of zander, Sander lucioperca in Beysehir Lake, were determined by using GC. Polyunsaturated fatty acids (PUFA) were found to be higher than saturated (SFA) and monounsaturated fatty acids (MUFA) in all seasons. Palmitic acid was the major SFA (57.0–64.0% of total SFA) in all seasons. Oleic acid was identified as the major MUFA (45.0–58.0% of total MUFAs). Docosahexaenoic acid (DHA), linoleic acid (LA), eicosapentaenoic acid (EPA), and arachidonic acid (AA) were the most abundant PUFA. Relating to the total fatty acid composition of zander, the percentages of DHA, LA, AA, and EPA ranged between 17.1–23.3%, 5.40–15.4%, 6.72–9.94% and 4.22–5.93% of total lipid, respectively. The percentages of total ω3 fatty acid were higher than those of total ω6 fatty acid in the fatty acid composition of zander with ω3/ω6 ratios of 1.49, 1.45, 1.22, 0.72 in spring, autumn, winter, and summer, respectively. It was shown that the fatty acid composition and ω3/ω6 fatty acids ratio in the muscle of zander were significantly influenced by spawning and season.  相似文献   

14.
To assess an impact of heated edible oils on intake of trans fat, the formations of trans fatty acids (TFAs) in cooking conditions was estimated by a frying and heating model system. For the frying model, sliced raw potatoes (10% of the frying oil (w/w)) were fried in commercially available canola oil at 160, 180 and 200 °C, and the 10 frying cycles were performed. The TFAs contained both in fried potatoes and in frying oils were measured by gas chromatography (GC). Lipids content of raw potatoes was about 0.1% (w/w) and TFAs in the raw potatoes were negligible. On the other hand, fried potatoes contained lipids at the level of 8.8%–9.2% and their fatty acid composition was mostly in correspondence with that of the frying oil. The TFAs amount of potatoes fried by the tenth frying operation was at the level of 0.99–1.05 g/100 g lipids. When 100 g potatoes fried in this process were consumed, the TFAs intake was estimated at less than 0.1 g. After 10 frying operations, TFAs content, acid values and peroxide values of the frying oils were measured and compared with those of corresponding heated canola oils without food. The amounts of trans 18:1 FAs contained both in the frying oil and in heated oil were less than the quantitative limit (0.047 g/100 g oil). The increases of trans 18:2 FAs and trans 18:3 FAs of the used frying oil were 0.02 g/100 and 0.05 g/100 g, respectively, compared with those of the fresh oil. trans 18:2 FAs accumulation in the heated oil was slightly less than that in the frying oil. To elucidate TFAs accumulation in various edible oils during cooking, six kinds of commercially available edible vegetable oils were heated to 180 °C in glass test tubes. Small changes in TFAs amounts were observed after four hours heating. These results suggested that an ordinary frying process using unhydrogenated edible oils has little impact on TFAs intake from edible oils.  相似文献   

15.
Fatty acid (FA) composition and isomeric trans unsaturated contents in selected brands of margarines and butter, which are more popular among general consumers of Pakistan, has been reported in this study. A sum of 10 butter and 10 margarine samples, collected from different bakers, confectioners and retail outlets, was analyzed. FA methyl esters were prepared, and quantitative measurements were made using a methyl lignoserate‐coated stationary phase, capillary column (SP‐2340, 60 m × 0.25 mm, 0.20 μm), with flame ionization detection. The contents of saturated FA, cis monounsaturated FA and cis polyunsaturated FA were in the following ranges: margarines 38.9–53.1, 21.9–35.8, 7.45–21.5% and butter 63.7–68.5, 23.0–27.0 and 1.20–2.94%, respectively. Results showed significantly higher amounts of trans FA (TFA) in margarines ranged from 2.45 to 21.1%, whereas butter samples contained less than 5.00% of TFA.  相似文献   

16.
Soybean oil was hydrogenated by a group of amorphous alloy nanocatalysts of nickel and boron (Ni–B). The Ni–B alloy catalysts showed activities dependent on synthesis conditions. The trans-fat contents in products hydrogenated by one Ni–B catalyst were approximately half of those when a commercial nickel catalyst was used. The Ni–B catalyst had a lower selectivity towards formation of trans-fatty acids but a higher selectivity towards formation of stearic acid than the commercial nickel catalyst. The increases in trans-fatty acids correlated linearly with the increases in C18:1 (oleic and elaidic acids) for nickel-containing catalysts. The incorporation of boron in nickel-containing catalysts increased the selectivity ratio (for forming stearic acid) but did not change the linolenic selectivity. Because of the simplicity to synthesize amorphous catalysts, this work may lead to future development of novel alloy nanocatalysts to synergistically reduce the formation of both trans- and saturated fatty acids in hydrogenated products.  相似文献   

17.
Margarines and shortenings available in Austria were repeatedly sampled in 1991/1992 and the content oftrans fatty acids (TFA) determined by using capillary GLC. Wide variations of the TFA contents with respect to intra- and inter-brand differences were observed. Diet margarines contained up to 1% TFA, while TFA concentrations in tub or stick margarines were much higher (15.7±5.8% and 21.3±5.3%, respectively). A sub-set of samples was also purchased in 1995 and a general reduction of the TFA content was noticed. Taking into account different market shares of certain margarine types, a weighted average of 15.7% TFA and 6.5% TFA was calculated for the 1991/1992 and the 1995 samples. Based on availability data the amount of TFA supplied with margarines was estimated to be 3.7 g per person per day, while a more accurate method of measuring dietary intakes, i.e. diet history and food frequency data, approximates the amount of TFA supplied with margarines to be 1.5 g per person per day for the 1991/1992 samples and 0.6 g for the 1995 samples.  相似文献   

18.
Margarines and shortenings available in Austria were repeatedly sampled in 1991/1992 and the content oftrans fatty acids (TFA) determined by using capillary GLC. Wide variations of the TFA contents with respect to intra- and inter-brand differences were observed. Diet margarines contained up to 1% TFA, while TFA concentrations in tub or stick margarines were much higher (15.7±5.8% and 21.3±5.3%, respectively). A sub-set of samples was also purchased in 1995 and a general reduction of the TFA content was noticed. Taking into account different market shares of certain margarine types, a weighted average of 15.7% TFA and 6.5% TFA was calculated for the 1991/1992 and the 1995 samples. Based on availability data the amount of TFA supplied with margarines was estimated to be 3.7 g per person per day, while a more accurate method of measuring dietary intakes, i.e. diet history and food frequency data, approximates the amount of TFA supplied with margarines to be 1.5 g per person per day for the 1991/1992 samples and 0.6 g for the 1995 samples.  相似文献   

19.
Consumers are increasingly aware that food components have the potential to influence human health maintenance and disease prevention, and dietary fatty acids (FA) have been of special interest. It has been 25 years since the last survey of US milk FA composition, and during this interval substantial changes in dairy rations have occurred, including increased use of total mixed rations and byproduct feeds as well as the routine use of lipid and FA supplements. Furthermore, analytical procedures have improved allowing greater detail in the routine analysis of FA, especially trans FA. Our objective was to survey US milk fat and determine its FA composition. We obtained samples of fluid milk from 56 milk processing plants across the US every 3 mo for one year to capture seasonal and geographical variations. Processing plants were selected based on the criteria that they represented 50% or more of the fluid milk produced in that area. An overall summary of the milk fat analysis indicated that saturated fatty acids comprised 63.7% of total milk FA with palmitic and stearic acids representing the majority (44.1 and 18.3% of total saturated fatty acids, respectively). Unsaturated fatty acids were 33.2% of total milk FA with oleic acid predominating (71.0% of total unsaturated fatty acids). These values are comparable to those of the previous survey in 1984, considering differences in analytical techniques. Trans FA represented 3.2% of total FA, with vaccenic acid being the major trans isomer (46.5% of total trans FA). Cis-9, trans-11 18:2 conjugated linoleic acid represented 0.55% total milk FA, and the major n-3 FA (linolenic acid, 18:3) composed 0.38%. Analyses for seasonal and regional effects indicated statistical differences for some FA, but these were minor from an overall human nutrition perspective as the FA profile for all samples were numerically similar. Overall, the present study provides a valuable database for current FA composition of US fluid milk, and results demonstrate that the milk fatty acid profile is remarkably consistent across geographic regions and seasons from the perspective of human dietary intake of milk fat.  相似文献   

20.
The total lipids and seasonal variations in the fatty acids of the mantle of cuttlefish (Sepia officinalis) captured in the north eastern Mediterranean were investigated and the mantle was found to be a good source of polyunsaturated fatty acids (ω3 PUFAs, in particular). In all seasons, the major fatty acids in the cuttlefish mantle were observed to be palmitic acid (16:0), stearic acid (18:0), eicosapentaenoic acid (EPA, 20:5ω3) and docosahexaenoic acid (DHA, 22:6ω3). A comparison of the saturated fatty acid (29.5–36.8%), monounsaturated fatty acids (7.81–9.84%) and polyunsaturated fatty acids (43.7–49.6%) of the cuttlefish mantle revealed that polyunsaturated fatty acids (PUFA) constituted the highest proportion. The levels of DHA in the cuttlefish mantle in autumn, winter, spring and summer were 27.6%, 28.5%, 29.5% and 23.9%, while those of EPA were 16.8%, 15.4%, 14.7% and 13.9%, respectively.  相似文献   

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