• Korean Journal of Food Science and Technology
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• v.30 no.1
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• pp.6-12
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• 1998

Degummed and bleached soybean oil was deodorized at a temperature range of $220{\sim}280^{\circ}C$ under the vacuum (4-5 torr) for 1 or 2 hrs. Gas chromatography with SP-2560 100 m capillary column was used to separate and quantitate fatty acid methyl esters and their isomers. Fatty acids were identified by comparing retention time with standards and GC-MS spectrum. The isomers of linoleic acid and linolenic acid in deodorized soybean oils were identified to be $C_{18:2}\;{\Delta}9-cis,\;{\Delta}12-trans,\;C_{18:2}\;{\Delta}9-trans,\;{\Delta}12-cis,\;C_{18:2}\;{\Delta}9-cis,\;{\Delta}12-cis,\;C_{18:3}\;{\Delta}9-cis,\;{\Delta}12-cis,\;{\Delta}15-trans,\;C_{18:3}\;{\Delta}9-trans,\;{\Delta}12-cis,\;{\Delta}15-cis,\;C_{18:3}\;{\Delta}9-cis,\;{\Delta}12-trans,\;{\Delta}15-cis,\;and\;C_{18:3}\;{\Delta}9-cis,\;{\Delta}12-cis,\;{\Delta}15-cis$. The formation of trans-fatty acids by deodorization at $240{\sim}280^{\circ}C$ for 2 hrs was in the range of 1.78 to 5.74%. Conclusively, the deodorizing conditions of $240^{\circ}C$ for 2 hrs or $250^{\circ}C$ for 1 hr were suggested as the best conditions which could minimize the formation of trans isomers of fatty acids in soybean oils.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.5
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• pp.699-704
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• 2006

Twenty-four cannulated Small-tailed Han${\times}$Poll Dorset wethers (BW $47.5{\pm}2.1kg$) were used to determine the effects of forage to concentrate ratio (40:60 vs. 70:30), monensin supplementation (0, 15 or 30 ppm, DM basis) and interactions of these two factors on cis-9, trans-11 conjugated linoleic acid (cis-9, trans-11 CLA) and trans-11 octadecenoic acid (trans11-$C_{18:1}$) concentrations in ruminal contents and plasma in sheep. The experiment was designed as a $2{\times}3$ factorial. The diet contained Chinese wild rye grass hay (Aneurolepidium Chinese), cracked corn, soybean meal, NaCl, limestone and trace mineral premix. Dietary crude fat and linoleic acid ($C_{18:2n-6}$) were adjusted with soybean oil to about 7.0% and 24.0 mg/g (DM basis), respectively. High forage diets increased (p<0.001) the concentrations of trans11-$C_{18:1}$ and cis-9, trans-11 CLA in ruminal contents and plasma. Monensin supplementation increased (p<0.001) the concentration of trans11-$C_{18:1}$ in ruminal contents, but had no effect on that of cis-9, trans-11 CLA. Concentrations of trans11-$C_{18:1}$ (p<0.019) and cis-9, trans-11 CLA (p<0.022) in plasma increased with dietary monensin levels. Interactions of forage: concentrate ratio and monensin level tended to affect the concentrations of trans11-$C_{18:1}$ (p<0.091) and $C_{18:2n-6}$ (p<0.083) in ruminal contents. Increasing forage levels increased the concentrations of trans11-$C_{18:1}$ and cis-9, trans-11 CLA in the rumen. Supplementing with monensin increased the ruminal production of trans11-$C_{18:1}$ and concentrations of trans11-$C_{18:1}$ and cis-9, trans-11 CLA in plasma.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.3
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• pp.325-337
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• 2003

This study was designed to determine the distribution of trans fatty acids (tFAs) isomers of Processed foods commonly consumed in Korea. The tFAs positional isomers were analyzed using GC/MS spectrometer with HP-23 cis/trans FAME, capillary column (50m $\times$ 0.20 mm, id., 0.2 ${\mu}{\textrm}{m}$ film thickness) for 41 food samples. TFAs isomers were identified by comparing retention time with standards and GC/MS spectrum. In margarines, the content of tFAs ranged from 4.0% to 25.16% and the most abundant positional isomer of tFAs was C18:1 $\Delta$9t. In oils and fats, lards contained higher levels of tFAs (5.70~16.54%) than shortenings (6.77~10.55%). Shortenings contained higher levels of C18:1 $\Delta$9t (3.1~5.1%) than lard (1.6~4.3%), but corn oils had no tFAs. In seasonings, mayonnaise had no C16:1 $\Delta$9t, whereas C18:3t was detected. The content of tFAs in confectioneries was wide (16.20~52.16%). Among them, instant popcorns contained the highest amount of tFAs. Milk and dairy products showed even distribution of tFAS such as C18:1t, C18:2t, and C18:3t. Predominant tFAS isomer of condensed milk and ice cream was C16:1 $\Delta$9t. Frozen french fries and fried chicken contained higher levels of C18:1$\Delta$9t (9.4%), whereas grilled pork (jowl) had no C18:1 $\Delta$9t. The amount of tFAs per serving size was the highest in popcorn, followed by frozen pizza, frozen french fries, fried chicken, and bakeries.

• Korean journal of food and cookery science
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• v.6 no.3 s.12
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• pp.25-32
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• 1990

In this study, the cis to trans isomerization of unsaturated fatty acids were investigated about Soybean oil (SBO), Corn germ oil (CGO), Cottonseed oil (CSO), Margarine (MG), Shortening (ST) incubated at $40{\pm}2^{\circ}C$ for 35 days and heated at $185{\pm}2^{\circ}C$ for 24 hours. The contents and kinds of trans fatty acids in each sample were determined by GLC after seperating by HPLC. The results were obtained as follows; 1. When samples were incubated at $40{\pm}2^{\circ}C$ for 35 days, the contents of total trans fatty acids were increased from $0.5{\sim}12.3%$ to $0.8{\sim}20.5%$. The kinds of trans fatty acids found were $t-C_{18:1},\;t,c-C_{18:2},\;t,t-C_{18:2},\;t,c,c-C_{18:3}$ in $SBO,\;t-C_{18:1},\;t,c-C_{18:2}$ in $CGO,\;t-C_{16:1},\;t-C_{18:1},\;t,c-C_{18:2},\;t,t-C_{18:2}$ in CSO. Processed oil such as MG and ST showed more complicated composition of trans fatty acids than SBO, CGO and CSO. $t-C_{18:1},\;t,c-C_{18:2},\;t,t-C_{18:2},\;t,c,t-C_{18:3},\;t-C_{20:1}$ were detected in ST. 2. In the case of heating at $185{\pm}2^{\circ}C$ for 24 hours, the contents of total trans fatty acid were $1.6{\sim}37%$. 2% in all samples. Heating made more remarkable isomerization than incubation $(40{\pm}2^{\circ}C)$. Specially, $c,c,t-C_{18:3}$ in $SBO,\;t,t,t-C_{18:3}$ in $MG,\;t,c,t-C_{18:3},\;t,t,t-C_{18:3}$ in ST were detected. 3. The total contents of trans fatty acids of processed oil were higher than vegetable oils. During incubation, trans fatty acids increased in the order of MG>ST>CGO>SBO>CSO, and during heat treatment, MG>ST>SBO>CGO>CSO.

• Korean journal of food and cookery science
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• v.5 no.1
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• pp.69-74
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• 1989

Trans fatty acids are formed during refining process of vegetable oils (deodorization), hydrogenation, the high temperature treatment of oils and rancidity. Trans fatty acids contents were measured in vegetable oils added to tuna, oyster and mussel Can by Glass Capillary Gas Chromatography. Also Acid Values, Peroxide Values, iodine Values and Saponification Values of vegetable oils added to Can were determined. The results were as follows; 1. Among vegetable oils added to Can, trans fatty acids isomer of cotton seed oil were mostly t,c-18:2 and t,c,c-18:3. 2. Total average contents of trans fatty acids of soybean oil added to tuna Can (Ab) were shown the highest values among tuna (Aa, Ab), oyster, mussel (Cb) Cans. 3. All of oils added to Can had been keeping safe quality during 1 year or more with low Acid and Peroxide Values.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.11
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• pp.1604-1609
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• 2003

A metabolism trial with four ruminally fistulated sheep was conducted in a $4{\times}4$ Latin square design to examine the effect of concentrate to roughage ratio (70:30 vs. 85:15) and oil source (soybean oil vs. rapeseed oil) on the ruminal fermentation pattern and $C_{18}$-fatty acids composition including trans11-$C_{18:1}$ (trans11-ODA) and cis9, trans11-18:2 (cis9, trans11-CLA) in the rumen fluid and plasma. Oil was added to the concentrate at 5% level of the total diet (DM basis) and chopped rye grass hay was fed as roughage. An increased level of concentrate (85%) within supplemented oil slightly lowered pH but increased ammonia concentration. Supplementation of rapeseed oil relatively increased pH and ammonia concentration. Higher concentrate level resulted in increased tendencies of total VFA concentration while oil source did not affect the total VFA concentration and VFA proportion. Whole tract digestibilities of DM, CP, EE, NDF and OM in diets slightly increased at higher concentrate level. Proportions of oleic acid ($C_{18:1}$) and linoleic acid ($C_{18:2}$) in the rumen fluid were influenced by the fatty acid composition of oil source but oil source did not affect the in vitro formations of trans11-ODA and cis9, trans11-CLA. Slightly increased trans11-ODA and cis9, trans11-CLA proportions, however, were observed from the sheep fed high roughage diet supplemented with both soybean oil and rapeseed oil. The $C_{18:1}$ and $C_{18:2}$ composition in supplemented oils responded to those in plasma of sheep. Effects of concentrate to roughage ratio and oil source on trans11-ODA and cis9, trans11-CLA proportions in plasma were found to be small. Proportion of cis9, trans11-CLA in plasma tended to be increased from the sheep fed high roughage diet and collection time at 9h post feeding.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.350-355
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• 2009

In this research, fatty acid composition and trans fatty acids of 22 selected meat products produced by Turkish companies were analyzed by capillary gas liquid chromatography (GLC). Total fat contents of the meat products ranged from 11.60-42.50%. Salami had the lowest fat content 11.60% and sucuk (soudjuk) the highest 42.50%. Major fatty acids were C$_{16:0}$, C$_{18:0}$, trans C$_{18:1}$, cis C$_{18:1}$, and C$_{18:2}$ in the samples. Total unsaturated fatty acid contents have changed from 38.73 to 70.71% of total fatty acids, and sausage had the highest percentage among the samples. The majority of samples contain trans fatty acids and the level ranged from 2.28 to 7.95% of the total fatty acids. The highest amount of total trans fatty acids was determined in kavurma (Cavurmas) (7.95%), and total trans fatty acids of meat products such as pastrami contained more than 5% of the total fatty acids.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.9
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• pp.1529-1536
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• 2004

This study was designed to determine total trans fatty acids (tFAs) content of processed foods commonly consumed in the Korean diet and to prepare the database for the estimation of tFAs intake in Koreans. Total fat and tFAs content was determined by Soxhlet extraction method and attenuated total reflection infrared spectroscopy (ATR-IR), respectively. The tFAs positional isomers were analyzed using GC/MS spectrometer. In margarines, the content of tFAs ranged from 8.27% to 28.53%. Shortenings contained higher levels of tFAs (1.98~11.33%) than lards (1.83~1.96%). The content of tFAs in grilled confectioneries was wide (7.37~26.54%). Instant popcorns contained the highest amount of tFAs. Fried chickens had 0.44 to 14.85% of tFAs and french fries had 5.18 to 27.01% of tFAs. In fried snacks (crispy) and chocolates, tFAs were not detected. The amount of tFAs per serving size was the highest in instant popcorn, followed by french fries, fried snack (tortilla), doughnuts, and grilled confectioneries. TFAs isomer of margarines was mostly C18:1${\Delta}$9t. In shortenings and lards, the most abundant positional isomer of tFAs was C18:1${\Delta}$9t and C18:2${\Delta}$9t ${\Delta}$12t. Correlation coefficient of tFAs content between IR and GC/MS method was $r^2$=0.91.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.2
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• pp.222-226
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• 2003

The effects of dietary sources of C18:2 n-6 or C18:3 n-3 fatty acids on the occurrence of conjugated linoleic acid (CLA) and time-dependent changes of free fatty acid fractions in rumen contents were investigated. Sheep (n=4) fitted with rumen fistula were used in a 44 Latin square design wxith each 14 d period. Sheep were fed one of four diets consisting of grass hay and concentrates in a ratio of 70:30. Dietary treatments were 100% concentrates (served as the control), and concentrates were replaced by safflower seed at 30% (SFS), safflower meal at 18% - safflower oil at 12% (SFO), and safflower meal at 18%-linseed oil at 12% (LNO). At the end of each experimental period, rumen contents from each sheep were collected before feeding and at 1, 3, 6 and 12 h after feeding. The levels of cis-9, trans-11 CLA in free fatty acid fraction were considerably increased in all treated groups relative to the control, but not significantly. The increase in cis-9, trans-11 CLA was slightly higher in SFS and SFO groups than group fed diet containing linseed oil. The level of cis-9, trans-11 CLA in free fatty acid fraction was reached to the maximum value at 1hr after feeding and, thereafter gradually decreased to near the value before feeding. The generation of trans-11 C18:1 was significantly higher in all treated groups than that of control. The level of trans-11 C18:1 was linearly increased after feeding of experimental diets, reaching the maximum value at 3 h. Feeding of diets containing polyunsaturated fats to sheep resulted in a marked increase in the levels of trans-11 C18:1 and a slight increase of CLA in free fatty acid fraction of rumen contents. Our results support that endogenous synthesis of CLA from trans-11 C18:1 may be involved the primary source of CLA in dairy product. (Asian-Aust.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.10
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• pp.1353-1361
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• 2009

This study investigated the effect of waxy barley on the incorporation trans fat (tFA) into plasma lipid and lipid profile through 6 weeks trial. 39 healthy volunteers were divided into 2 groups and fed waxy barley bread (WBG) or wheat bread (WG) containing equivalent amounts of tFA (elaidic acid rich, 3.75 g/day), respectively. Plasma lipid profiles and fatty acid composition at 0, 2, 4, 6 weeks after a respective bread were studied. Plasma lipid was extracted by the method of Folch, esterified by acid transmethylation and analyzed by gas chromatography. The fatty acid composition reflected the fatty acid proportion of the test fat. However, consumption of waxy barley bread with tFA for 6 weeks affected plasma fatty acid composition including tFA. Incorporation of tFA into plasma lipid was significantly lowered compared to WBG than in WG after 6 weeks of consumption. Furthermore, saturated fatty acids such as C16:0 and C18:0 levels were also significantly lowered in WBG than in WG. Furthermore, plasma total cholesterol level and TG/HDL-cholesterol ratio were also significantly lowered in WBG compared to WG at 2, 4 and 6 weeks. These results suggest that waxy barley bread with high $\beta$-glucan lowered plasma trans, saturated fatty acid and total cholesterol levels though the inhibition of lipid absorption.