• The Korean Journal of Food And Nutrition
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• v.10 no.4
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• pp.564-573
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• 1997

The addition of antioxidants to fats and oils is one of the most effective ways to prevent oxidation of lipids. The popularity of natural antioxidants has increased because of the possible toxicity of synthetic antioxidants. Common natural antioxidants, tocopherols, retard oxidation at ambient temperatures, but they are ineffective at retarding oxidation at frying temperatures. The need for the development of novel natural antioxidants which are effective at frying temperatures is obvious. Sterols present in vegetable oils and certain herbal plant extracts have been reported to have antioxidant properties. Some sterols have been shown to retard thermal changes at frying temperatures. All the sterol effective at preventing oxidation at frying temperatures have an ethylidene group in their side chain. These effects can be explained by the hypothesis that sterols with a structure that allows them to react with lipid free radicals to form relatively stable free radicals are effective as antioxidants. (Key words :natural antioxidants, sterols, ethylidene group, herbal plant extracts)

• New & Renewable Energy
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• v.8 no.4
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• pp.38-43
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• 2012

Biodiesel is non-petroleum based fuel produced from vegetable oils or animal fats through transesterification. The compositions of saturated and unsaturated fatty acids in the feedstocks are important factors for biodiesel quality in terms of low-temperature fluidity and oxidative stability. The goal of this study is to improve the cold flow property of biodiesel from vegetable and animal origin containing highly saturated methyl esters (approx. 50%). In this purpose poly-saturated methyl esters in palm and tallow biodiesel were removed via urea-based fractionation and then the recovered fractions (enriched unsaturated fatty acid methyl esters) were supplemented with cold flow improvers. The highest concentration of unsaturated fatty acid methyl esters (93.8%) was obtained using a urea/fatty acid ratio of 3:1 at the crystallization temperature of $0^{\circ}C$ for 17 hours in incubation, with recovery of 71% and the addition of cold flow improver (Flozol$^{(R)}$ 515, 3,000 ppm) to the enriched poly-unsaturated fatty acid methyl esters reduced the CFPP(cold filter plugging point) of palm biodiesel from $12^{\circ}C$ to $-42^{\circ}C$. In tallow biodiesel both the enrichment of unsaturated fatty acid methyl esters (93.71%) and the addition of cold flow improver (Infineum R408, 3,000ppm) reduced the CFPP from $10^{\circ}C$ to $-32^{\circ}C$.

• Microbiology and Biotechnology Letters
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• v.39 no.3
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• pp.238-244
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• 2011

Biodiesel, mono-alkyl esters of long chain fatty acids, is one of the alternative fuels derived from renewable lipid feedstock, such as vegetable oils or animal fats. For decade, various lipases have been used for the production of biodiesel. However, the production of biodiesel by enzymatic catalyst has profound restriction in industry application due to high cost. To overcome these problems, many research groups have studied extensively on the selection of cheap oil sources, the screening of suitable lipases, and development of lipase immobilization methods. In this study, we produced biodiesel from plant oil using Proteus vulgaris lipase K80 expressed in Escherichia coli cells. The recombinant lipase K80 was not only expressed in high level but also had high specific lipase activity and high stability in various organic solvents. Lipase K80 could produce biodiesel from olive oil by 3-stepwise methanol feeding method. The immobilized lipase K80 also produced biodiesel using the same 3-stepwise method. The immobilized lipase could produce biodiesel efficiently from various plant oils and waste oils.

• Journal of the Korean Society of Food Culture
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• v.10 no.3
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• pp.185-200
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• 1995

In this survey, we investigated the way of thinking about meal management of housewives including the sincerity to meal preparation, the eating practices and cronic degenerative diseases related dietary behaviors, and studied the effects of above factors on the real food intakes. We also investigated the trends of health-foods and nutrient supplements usage. The results obtained from 506 housewives in Seoul were summarized as follows. Although our subjects prepared their meals habitually without special concern, they did not prefer the use of convenient foods. The food prefrence of housewivess who had more child and refered higher life status was similar with other family members. The dietary attitudes were good in large family, the higher income and the more child group. The highly educated group skipped breakfast more frequently. The mealmanagers with better education career and good living status considered for the restriction of salty foods, sweet foods, animal fats and pungent foods, and for the nutritionally balanced diet. The high income group showed great concerns about weight gain at meal times. The nutritional qualities expressed by the frequency of food group intakes were high in the better educated and living status groups, and their eating frequencies of animal protein foods and calcium sources were significantly high. Mealmanagers who had no job intaked vegetable oils through frying foods frequently. The use of health-foods and nutrient supplements was influenced by age, educational and economic level and self-estimated living status, but the trends in prevalence of both were not consistent. Health-foods were prefered by the groups of high educational career, affluent income and advanced living status, and low educational career, low income and low living status groups favored the nutrient supplements. The restrictive intake of animal fat and the use of health-food were positively correlated, which seemed that the subjects used health-foods as supplements in compensation for nutritional unbalance caused by the avoidance of animal protein foods.

• Journal of the Korean Dietetic Association
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• v.26 no.4
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• pp.289-305
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• 2020

Picky eating behavior is a significant factor in causing unhealthy eating and disturbing the growth of children. This study examined picky eating behaviors and food intake of 112 preschoolers aged 3~5 year, picky eaters (n=41) and non-picky eaters (n=71), living in Dobong-gu, Seoul metropolitan area, South Korea. Picky eating questionnaires and three consecutive 24-hour dietary recalls were collected from their caregivers. The difference between the two groups was verified using a Chi-square test or t-test and Pearson's correlation. Compared to the non-picky eaters, fussiness, satiety responsiveness, and refusal of food variety were significantly higher in picky eaters (P<0.001). Compared to the non-picky eaters, an assessnent of the preschooler's behavior and the caregivers' perception were positively correlated in picky eaters (r=0.749, P<0.001). The intakes of shellfish (P<0.05), vegetables (P<0.001), fiber, vitamin E (P<0.01), vitamin A, and folate (P<0.05) were significantly lower in picky eaters than the non-picky eaters. The major food sources of vitamin A and folate were vegetables, of which grains were the source of fiber, fats and oils were the source of Vitamin E, and root vegetables were source of vegetables in both picky and non-picky eaters. In conclusion, picky eating behaviors are related to different fussiness and slowness in eating. Therefore, it is suggested to increase the amount of meal and vegetable intake in picky eaters.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.700-704
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• 1997

Fermentation and morphological characteristics of rice bread baked with gums, lipids, and glutens added dough were investigated to establish the standard recipe for rice bread processing. All gum-type additives 1ed to successful formation of rice bread. Hydroxypropyl-methyl-cellulose among tested gums showed the best volume expansion and successful formation of rice bread. Addition of vegetable oils gave better effect on increasing the specific loaf volume and tenderness of rice bread than addition of the solid-type lipids such as margarin and lard during rice bread processing. Dry heating during baking of the rice bread gave more desirable effect on specific gravity of rice bread than wet heating. High-amylose rices such as Suweonjo, AC 27, and IR 44 showed better formation of rice bread in the case of adding 3% hydroxypropyl-methyl-cellulose, while Suweon 230 and Pusa-33-30 showed slightly better formation of rice bread in the case of adding the gluten and strong hard flour. The glutinous rice Hangangchalbyeo failed to the formation of rice bread in both cases of adding 3% hydroxypropyl-methyl-cellulose and the gluten and hard flour.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.1
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• pp.83-87
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• 2008

We have a lot of interest in alternative fuels to provide energy independence from oil producing country and to reduce exhaust emissions for air pollution prevention. Biodiesel, which can be generated from natural renewable sources such as new or used vegetable oils or animal fats, may be used as fuel without change of engine structure in diesel engine of compression ignition engine. In this paper, the test results on specific fuel consumption and exhaust emissions of neat diesel oil and biodiesel blends(10 vol.% biodiesel and 20 vol.% biodiesel) were presented using four stroke, direct injection diesel engine. Especially this biodisel was produced from rape oil at our laboratory by ourselves. This study showed that specific fuel consumption and NOx emission were slightly increased, on the other hand CO emission and Soot were tolerably decreased more in the case of biodiesel blends than neat diesel oil.

• 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 Health Education and Promotion
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• v.23 no.5
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• pp.1-11
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• 2006

Objectives: The 2003 WHO/FAO technical report described that Korea has largely maintained its traditional high-vegetable diet despite major social and economic changes, and had lower than expected levels of obesity prevalence than other industrialized countries. However, the prevalence of obesity in Korea has recently been rapidly increasing. The aim of this study was to elucidate the determinants of this rapid growth of obesity prevalence in Korea and to compare the results of national nutrition surveys between Korea and Japan. Methods: The trends of the National Health and Nutrition Survey in Korea instituted every 3 years and that in Japan conducted every year were compared. The results of obesity prevalence defined as more than 25 of the Body Mass Index, the percentage of habitual exercisers and the results of the nutritional surveys were examined from 1992 to 2005 in Korea and from 1992 to 2004 in Japan. Results: The prevalence of obesity in males has been gradually increasing in both Korea and Japan since 1992. Though until 1995 the prevalence of obesity in the Korean male population was less than that in Japan, after 1998 Korea surpassed Japan and a markedly increasing trend was observed. In females, the increasing trend of obesity was slower than males in both Korea and Japan. However, the prevalence of obesity was much higher in Korea compared with that in Japan. The percentage of exercisers was much lower in Korea than in Japan. Although, the definition of an exerciser varies with the survey year in Korea and is different from that in Japan, almost 70% of the population was not regularly engaging in moderate or hard intensity exercise in Korea. From 1995, the total energy intake was increased by 9.8% in Korea but it was decreased by 6.9% in Japan. Presently, the energy intake per capita per day in Korea exceeded that in Japan. Remarkable increases in the intake of meat and poultry, vegetable oils and fats, and milk and dairy products were observed in Korea from 1995 to 2005. On the other hand, these values decreased during the same period in Japan. Conclusion: The prevalence of obesity in Korea is increasing and has surpassed that of Japan. The current trends could be attributed to the low prevalence of habitual exercisers, and an increase in energy intake and the proportion of energy intake from fat.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.2
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• pp.122-136
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• 1983

The effect of dietary casein, calcium, magnesium and some vegetable oils such as seasme, perilla and soybean oil on the serum cholesterol level in the rabbit were studied for a period of 5 weeks using isocalories and isonitrogenous as basal diets. The experimental rabbits fed the following basal diets containing crude protein 68.47%, carbohydrates 13.35%. fats 16.18% and vegetable oil 10%. casein 10%, calcium and magnesium according to experimental plan making. In order to calculate the feeding efficiency, protein efficiency and calorie efficiency during period, the body weight gains were measured at the same time using same balance, respectively. The results are summarized as follows. Body weight gains per week of the group fed perilla oil, calcium and basal diet were the higher than any other groups. And body weights gains per week of the group fed basal diet, vegetable oil were the lower than any other groups. In the case of efficiency of reed, protein and calorie, the efficiency ratios of the group fed perilla oil were the higher than any other groups. Especially, perilla oil and calcium diet effect on body weight gain in rabbit. In the case of serum protein, the total proteins in serum were almost same value for all the groups. Serum albumin of group fed basal diet. vegetable oil and casein were the higher than any other groups. The ${\alpha}$-globulin of the groups, fed basal diet and calcium was the lower than any other grosps. The ${\beta}$-globulins of the groups fed basad diet, perilla oil and casein were the highest value. In serum lipoprotein, lipalbumin was almost same value for the groups fed vegetable oil, but fed vegetable oil and calcium diet was the lowest value. The ${\beta}$-lipoprotein in high cholesterol level group was increased some degree, the group fed perilla oil added was lower. The ratio of ${\beta}$-lipoprotein per lipalbumin was from 0.11 to 0.26. The ratio of lipalbumin per total lipoprotein was high in calcium and soybean oil added diet. In serum triglyceride, the level of triglyceride of groups fed seasme oil or perilla oil was the higher than any othe groups, but in the group fed casein and calcium or magnesium, the level of triglyceride level was decreased. Calcium and magnesium effect on triglyceridge level lowering action. In serum total cholesterol, the group does fed vegetable oil with basal diet and casein added more, total cholesterol level increased as much as triglyceride level increased. But the group does fed perilla oil and magnesium shows total cholesterol level decreased remarkably. In the group fed basal diet with calium, the amount of serum calcium was increased, but of serum magnesium was decreased. In the case of blood glucose, the group fed basal diet and vegetable oil was decreased. According to the regression and correlation coefficient in blood components in rabbit, there are positive correlation $${\gamma}{\sim_=}1$$ between serum cholesterol and triglyceride, ${\beta}$-lipoprotein, ${\alpha}$-globulin, calcium and magnesium according to diet composition. From the above results, the serum cholesterol level lowering factors in rabbit, was the amount of triglyceride and ${\beta}$-lipoprotein which was decreased in perilla oil fed. It assumes that serum cholesterol and triglyceride level lowering factors are not only unsaturation degree of fatty acid but the amount of calcium and magnesium and the ratio calcium per magnesium 2:1 in the diet.