• 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 Nutrition and Health
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• v.23 no.1
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• pp.19-24
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• 1990

Trans fatty acids are formed during processings of oils such as refining, hydrogenation and heat treatment at high temperature. Recently, interesting on whether trans fatty acids involve in development of atherosclerosis and cancer are getting more attentions. This study was to investigate contents of trans fatty acids in food served at domitories of a women's university in Seoul and also amount of the trans fatty acids consumed by the students. Food items were divided into five groups. Their contents of the trans fatty acids were, in the order of decreasing, 12.7% for cookies and cakes, 1.23% for fried foods, 0.98% for fried and sauted animal foods, 0.74% for milk and milk products and 0.72% for fried and sauted vegetables. Amount of trans fatty acids consumed by the students was 0.63g per day per person.

• Journal of the Korean Society of Food Culture
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• v.23 no.4
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• pp.469-478
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• 2008

In this study, degree of rancidity and trans fatty acid formation were examined in fat and oils, including soybean oil (SB), canola oil (CA), corn germ oil (CO), olive oil (OL), palm oil (PO), and beef tallow (BT), during heating for 10-130 minutes at 160-200$^{\circ}C$. In order to determine the rancidity of the fat and oils, acid values (AV), iodine values (IV), viscosity, and color were measured. Changes in the amounts of fatty acids and the formation of trans fatty acids were measured using GC and HPLC. For all groups, AV increased, IV decreased, and coefficients of viscosity and color increased as the heating temperature and heating time increased, indicating there were positive correlations between the heating temperature and time and AV. In addition, all groups had similar amounts of trans fatty acids, with the exception of the beef tallow; however, its level only slightly increased with heating. The olive oil had the lowest trans fatty acid content and the lowest amount created by heating. The order of trans fatty acid amounts generated while heating was BT>PO>CO>CA>SB>OL. According to the study results, the deep frying temperature during cooking should be 160-180$^{\circ}C$ in order to reduce AV and the amount of trans fatty acids that are formed. In addition, it is better to remove beef tallow during cooking and avoid heating at high temperatures since it results in high levels of trans fatty acids. The correlation between the amount of trans fatty acids and AV was positive, while the correlation between the amount of trans fatty acids and IV was negative, indicating that AV and trans fatty acid levels increase while IV decreases as the deep frying temperature and time increase. From the results, it was found that reducing the deep frying temperature and time can lessen increases in AV and trans fatty acids, and decrease IV. Accordingly, to reduce AV and trans fatty acid formation, the ideal deep frying conditions would be to use olive oil or soybean oil rather than beef tallow or palm oil at a temperature of 160-180$^{\circ}C$.

• Preventive Nutrition and Food Science
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• v.11 no.3
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• pp.253-256
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• 2006

The purpose of this study was to develop a gas chromatographic (GC) method to analyze fatty acids in milk fat with a single injection. The single-injection GC method we developed for analyzing fatty acid composition can separate a wide range of fatty acid methyl esters from butyric acid to docosahexaenoic acid. It separated 6 isomers of 18:1 (cis-6, cis-9, cis-11, trans-6, trans-9 and trans-11), 4 isomers of 18:2 (cis-9-cis-12, trans-9-trans-12, cis-9-trans-12 and trans-9-cis-12), and 4 isomers of conjugated 18:2 (cis-9- trans-11, trans-9-cis-11, cis-10-trans-12 and trans-10-cis-12).

• Korean journal of food and cookery science
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• v.6 no.2
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• pp.37-50
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• 1990

The cause and the degree of the cis to trans isomerization were investigated about soybean oil (SBO), corngerm oil (CGO), cottonseed oil (CSO), margarine (MG) and shortening (ST). All samples treated with various conditions were analyzed to determine physicochemical characteristics (AV, POV, IV, RI), fatty acid composition, total trans fatty acid content and change of trans fatty acid composition by GLC, IR and HPLC. The results were obtained as follows; 1. Physicochemical constants were changed with a gentle slope according to incubating period at 40${\pm}$2$^{\circ}C$ and physicochemical constants of margarine and shortening were changed, significiantly. 2. The saturation degree in the unsaturated fatty acid composition determined by GLC gradually were increased during incubation and heating periodically. For palmitic-and stearic acid content at the samples stored in the incubator, the saturation degrees were gradually increased. But for the case of heat treatment, they were increased more rapidly than other fatty acids. 3. Total trans fatty acid contents in each samples were determined by GLC, IR and HPLC, the amount of trans fatty acids were measured with discrepancy. It was caused by deviation of analytical instruments, methods and the kinds of samples. Trans fatty acids were measured more definitly in IR more than GLC and HPLC. On the other hand, total trans fatty acid contents in average levels for SBO, CGO, CSO, MG and ST stored for 35 days and heated for 24 hours were 1.3%, 1.1%, 0.9%, 22.6% and 13.8%, and 3.6%, 3.0%, 2.8%, 41.2% and 20.8%, respectively.

• 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.23 no.6
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• pp.1015-1024
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• 2007

Trans-fatty acids (TFAs) are defined as the sum of all unsaturated fatty acids that contain one or more non-conjugated double bonds in a trans configuration. Dietary trans- fatty acids originate from commercially hydrogenated oils and from dairy and meat fats. From the perspective of the food industry, partially hydrogenated vegetable oils are attractive because of their long shelf life, stability during deep-frying, and semisolidity, which can be customized to enhance the palatability of baked goods and fried foods. Although no definite differences have been documented so far between the metabolic and health effects of industrial and ruminant TFAs, the intake of industrially produced TFA has declined, and in Europe, the majority of TFAs are of ruminant origin. Due to the scientific evidence associating TFA intake with increased risk of coronary heart disease (CDH), the Korea Food and Drug Administration (KFDA) issued a final rule that requires the amount of trans fat present in foods to be declared on the nutrition label, by December 1, 2007. In addition, many food manufacturers who use partially hydrogenated oils in their products have developed, or are considering ways, to reduce or eliminate trans-fatty acids from certain food products.

• 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.

• Korean Journal of Food Science and Technology
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• v.17 no.3
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• pp.219-222
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• 1985

Fatty acid patterns were determined for 11 and 19 brands of household margarines from the local markets in Korea in 1983 and 1984, respectively. Gas-liquid chromatographic analyses on OV-275 column showed that the average content of total trans fatty acids was 18% ranging from 6.2 to 35.5% for the margarines produced in 1983. The prototype of trans fatty acids was trans-octadecenoic acid. There was a small amount of c, t-or t, c-octadecadienoic, whereas there were practically no t, t-octadecadienoic acid. Trans fatty acids was increased in proportion to linoleic acid contents. For the margarines produced in 1984.. percentage of trans fatty acids tended to decrease, while that of linoleic acid was increased as compared with the corresponding values for the 1983 products. Thus, the P/S ratio was increased markedly in the soft type margarines produced in 1984. However, Korean margarines contained seemingly less linoleic acid than that contained in Japanese margarines.

• 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.