• Korean journal of food and cookery science
• /
• v.25 no.3
• /
• pp.357-364
• /
• 2009

The objectives of this study was to explore the knowledge, attitudes, and perceptions of elementary school students towards trans fatty acids. In addition, the students' preferences and consumption frequencies of processed food items containing trans fats, as well as their food behaviors relating to snack consumption, were investigated. The study population consisted of students from seven provinces, including Seoul, Busan, Daegu, Kwangju, Gyungnam, Chungnam, and Kangwon. Two schools were selected in each province and one class was randomly chosen in each school. All students from the selected classes were surveyed onsite (N=951). The data were analyzed with chi-square tests and t-tests using SPSS/Windows (ver.15.0) program. The results showed that the students' knowledge levels toward trans fatty acid were very low, particularly on the production process of trans fats. The students perceived that trans fatty acids can cause health problems and should be consumed in low amounts. They also felt there is a need for a good nutrition education on trans fats. Furthermore, the students responded that their most preferred foods were in the order of breads, biscuits, and snacks. The most frequently consumed snack item among 2nd graders was biscuits and among 5th graders it was breads. It was also found that 90% of the students had snacks once a day, and of them, 58% prepared their own snacks. Based on this, we propose that students who allowed to choose their own snacks should be carefully educated on trans fatty acids to prevent excessive consumption of high trans fat foods.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.38 no.8
• /
• pp.1042-1049
• /
• 2009

It has been reported that trans fat (tFA) may have adverse or beneficial effect depending upon the position and number of double bonds. The presence of tFA in human tissues and fluids is related to dietary intake, intestinal absorption, metabolism and storage, exchanges among compartments. This study investigated the effect of breads containing tFA, soybean or rice on postprandial plasma fatty acid and lipid composition. 33 healthy volunteers were divided into 3 groups and fed soybean bread, rice bread or wheat bread groups containing equivalent amounts of tFA (elaidic acid rich, 3.75 g/day), respectively. Postprandial lipid profiles at 0, 1, 2, 3 and 4 hours after a respective meal were studied. Plasma fatty acid was extracted by the method of Folch and methyl ester of fatty and prepared by acid transmethylation and analyzed by Gas Chromatography. Peaks were identified using pure reference compounds and quantified. Postprandial data indicated that consumption of soybean and rice breads with 3.75 g tFA retarded the appearance of C18:1 and C18:2 tFA in plasma lipid compared to that of wheat bread. Futhermore, soybean and rice bread groups showed lower plasma saturated fatty acid levels than wheat bread group. Postprandial TG level was significantly lowered in soybean bread group compared to that of rice and wheat bread groups. These results imply that soybean bread with high dietary fiber content and biologically active substances may inhibit or delay lipid absorption.

• Asian-Australasian Journal of Animal Sciences
• /
• v.24 no.6
• /
• pp.800-809
• /
• 2011

The objective of this study was to investigate the effects of different ratios of corn silage (CS): alfalfa hay (AH), and extruded soybeans (ESB) on milk yield, milk composition, blood metabolites, and fatty acids in milk fat and plasma. Ninety multiparous Holstein cows were arranged in a randomized block design experiment which lasted 14 weeks. Treatments were arranged as a $3{\times}3$ factorial with 0%, 5% or 10% ESB (dry matter basis) and three forage treatments: I) 30% CS, 10% AH and 10% Leymus chinense hay (LC); ii) 20% corn silage, 20% alfalfa hay and 10% LC; iii) 10% CS, 30% AH and 10% LC. Cows were allowed to consume a total mixed ration ad libitum. There was no change of dry matter intake when cows were fed the experimental diets. As more AH was added to the diets, milk yield, milk protein content and yield, and trans9, cis11-conjugated linoleic acids (CLA) concentrations in milk fat and plasma increased. When ESB were supplemented to the diets, milk yield, and trans9, cis11-CLA concentration in milk fat and plasma increased. When 10% ESB was added to the diet containing 30% AH the trans9, cis11-CLA content (1.46 g/100 g of total fatty acids) in milk was the highest among all treatments. These results suggests that AH could replace part of a CS diet and be a good forage source of diet for dairy cows to improve milk yield and milk composition. Meanwhile, ESB could be included in the diet with high AH to improve production performance of dairy cows.

• Korean journal of food and cookery science
• /
• v.25 no.5
• /
• pp.600-605
• /
• 2009

This study was conducted to investigate the fat content, fatty acid composition, trans fatty acid content, and acid value of twenty types of fried chickens purchased in local markets in Korea. The fat was extracted from the fried chickens and analyzed by the folch method, which revealed that the content ranged from 4.94% to 18.06%. The major fatty acids in the fried chickens were oleic acid ($29.78{\sim}67.85%$), linoleic acid ($8.42{\sim}39.54%$), and palmitic acid ($10.67{\sim}25.43%$). Twenty types of fried chickens contained less than 0.1 g of trans fatty acid per 100 g of chicken, while the fatty acid value ranged from $0.86{\sim}2.65$, which is lower than the KFDA criteria.

• Asian-Australasian Journal of Animal Sciences
• /
• v.19 no.5
• /
• pp.699-704
• /
• 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 East Asian Society of Dietary Life
• /
• v.17 no.4
• /
• pp.540-546
• /
• 2007

Bakery food items distributed in Chung-cheong province Daejeon, Cheonan, and Cheongju) were studied to determine their contents of total crude fat and trans fatty acids (TFA). After fat extraction by the Folch method, methylation was carried out to analyze the fatty acid compositions by GC, using a SP-2560 column and flame ionization detector. The total fat contents of the foods were in the approximate range of 2$\sim$34%. The total fat contents of the items were as follows: whipping cream cake : 0.03$\sim$1.31 (g/100 g food), pastries = 0.21$\sim$2.64 (g/100 g food), cream puff = 0.09$\sim$0.43 (g/100 g food), croquette = 0.22$\sim$1.99 (g/100 g food), and glutinous rice doughnut = 0.03$\sim$0.38 (g/100 g food).

• Journal of Animal Science and Technology
• /
• v.44 no.4
• /
• pp.427-442
• /
• 2002

Conjugated linoleic acid(CLA) is a collective term for a group of positional (c8, c10; c9, c11; c10, c12, and c11, c13) and geometric(cis,cis; cis,trans; trans,cis; and trans,trans) isomers of octadecadienoic acid (linoleic acid) with conjugated double bond system. CLA has been shown to have a variety of biological effects. Major effects of CLA on health, such as anti-cancer, anti-oxidation, anti-atherosclerosis and improving immuno-responses, might be derived or partially derived from the alternated lipid metabolism after CLA feeding. Most of studies on the effect of CLA on fat metabolism are concentrated on rats, mice, pigs and other mammals. The CLA inhibited carcinogen-induced neoplasia in several animal models and inhibited the proliferation of human malignant melanoma, colorectal and breast cancer cells and CLA reduced the atherosclerosis. Several studies have determined the antioxidant property of CLA; however, the property still remains controversial. Some of the studies have shown that CLA acted as an antioxidant, whereas some other studies have demonstrated that CLA might be a prooxidant. Several studies suggested that CLA could reduce fat accumulation in mammals. CLA was suggested to promote muscle growth and reduce fat deposition in mouse, and improve feed efficiency in rats. CLA has been shown to inhibit the activity of stearoyl-CoA reductase. CLA also reduced the content of arachidonic acid. Since arachidonic acid, and eicosapentaenoic acid (EPA) and docosahexenoic acid (DHA) are synthesized by different pathways, reducing the synthesis of arachidonic acid may not mean reducing that of EPA and DHA. Many sutdies have been shown biological effects of CLA. Therefore, further research is needed to answer the following questions: 1) how to synthesize the new CLA by new methods, 2) why CLA has shown biological effects, 3) how to increase CLA effects in animal products.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.1
• /
• pp.73-78
• /
• 2012

Excessive intake of trans fats is known to be a risk factor for cardiovascular diseases. Previously, we have shown that green tea extract (GTE) lowers the intestinal absorption of lipids and lipid-soluble compounds in rats. This study was conducted to investigate a possible role of GTE on the lymphatic absorption of elaidic acid, a major trans fat in the diet. Adult male Sprague-Dawley rats with lymph duct cannula were infused via an intraduodenal catheter at 3.0 mL/hr for 8 hr with a lipid emulsion containing $180.0{\mu}mol$ elaidic acid, $400.0{\mu}mol$ triolein, $20.7{\mu}mol$ cholesterol, $3.1{\mu}mol$ ${\alpha}$-tocopherol, and $396.0{\mu}mol$ sodium-taurocholate with or without (control) GTE in a 24 mL PBS buffer (pH, 6.4). Simultaneously, lymph was collected hourly for 8 hr via the lymph duct cannula. There was a significant difference in lymph flow by GTE. Also, the lymphatic absorption of elaidic acid for 8 hr was significantly lower in rats infused with GTE than in those not infused with GTE. Similarly, GTE infusion decreased the lymphatic outputs of cholesterol, oleic acid, and phospholipids, compared with the controls. These findings provide clear evidence that GTE has an inhibitory effect on the intestinal absorption of elaidic acid and other lipids. Our work here provides the foundation for further studies to examine and evaluate dietary strategies to ameliorate dietary trans fats from the diet.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.40 no.11
• /
• pp.1562-1568
• /
• 2011

We studied the amounts of trans fatty acids and saturated fatty acids in child-favored foods. Confectioneries, breads, donuts and hamburgers were included in this study. The total fatty acid content and the amount of each type of fatty acid were determined by gas chromatography with a flame-ionized detector. Confectioneries were shown to have the highest content of crude fat. The mean content was 24.2${\pm}$6.9 (range: 4.6~41.1) g/100 g food. The mean content of crude fat in donuts, bread and hamburgers was 23.9${\pm}$5.8 (range: 14.1~39.5) g/100 g food, 15.7${\pm}$7.9 (range: 1.4~30.0) g/100 g food, and 9.5${\pm}$3.4 (range: 4.5~18.5) g/100 g food, respectively. Bread had the most trans fatty acids at 1.3 g/100 g food. This result inferred that manufacturers have tried to reduce the trans fat content. The mean content of saturated fatty acids in confectioneries, donuts, bread, and hamburgers was 11.6${\pm}$4.8 (range: 2.0~22.7) g/100 g food, 11.2${\pm}$4.0 (range: 4.8~23.2) g/100 g food, 6.9${\pm}$4.1 (range: 0.6~15.4) g/100 g food, 3.0${\pm}$1.0 (range: 1.0~5.8) g/100 g food, respectively. This content depended on crude fat. The composition of fatty acids varied according to the oil and fat used in the manufacturing process of each food, and the natural content. Foods that were fried in vegetable oil tended to be especially low in saturated fat.

• Korean Journal of Food Science and Technology
• /
• v.41 no.2
• /
• pp.173-178
• /
• 2009

Epidemiological studies showed that high trans-fat consumption is closely associated with getting the risks of cardiovascular disease. The objective of this study was to produce trans-free fat through lipase-catalyzed interesterification, as a substitute for the cream margarine commonly used in industry. Optimum conditions for interesterification in a packed bed enzyme bioreactor (PBEB) were determined using response surface methodology (RSM) based on central composite design. Three kinds of reaction variables were chosen, such as substrate flow rate (0.4-1.2 mL/min), reaction temperature (60-70$^{\circ}C$), and ratio of fully hydrogenated canola oil (FHCO, 35-45%) to evaluate their effects on the degree of interesterification. Optimum conditions from the standpoint of solid fat content (SFC) were found to be as follows: 0.4 mL/min flow rate, 64.7$^{\circ}C$ reaction temperate, and 42.8% (w/w) ratio of FHCO, respectively. The half-life of immobilized lipase in PBEB with two stages at 60$^{\circ}C$ ($1^{st}$ stage) and 55$^{\circ}C$ ($2^{nd}$ stage) was about more than 30 days as estimated by extrapolating the incubation time course of tristearoyl glycerol (TS) conversion, whereas the half-life of the enzyme in PBEB with single stage at 65$^{\circ}C$ was only about 15 days. Finally, the results from SFC analysis suggest that trans-free fat produced in this study seems to be a suitable substitute for the cream margarine commonly used in industry.