• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.6
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• pp.1032-1037
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• 1994

A simple, reproducible , and accurate enzymatic method using a cholesterol assay kit was developed to quantify total cholesterol content in egg yolk. Total egg yolk lipid was extracted with hexane : isopropanol(3 : 2, v/v) mixture. Samples containing various amount of the total lipid(0-3mg) in optically identifical culture tubes were reacted for 10 min in a water bath (37$^{\circ}C$) with the enzyme solution (5ml) from the cholesterol assay kit. Cholesterol content of the reaction mixturesin culture tubes was spectrophotometrically determined by two different ways : (1) using the culture tube as a curvette(designate culture tube method ; CTM) and (2) the quartz cvette containing the reaction mixture transferred from the culture tube (designate standard cvette method, SCM). CTM revealed lower cholesterol content in 0.1-1.0mg lipid sample range that SCM did, but not significant. For more than 2.0mg lipid sample, CTM gave significantly (p<0.01) lower cholesterol content relative to that by SCM, suggesting that SCM give a false positive result from the sample containing more than 2 mg lipid due to the interference of absorbance by lipid dispersed in the reaction solution . Cholesterol content of less than 1.0mg lipid sample by CTM was proportional to the amount of lipid used, but its linear relationship was not seen in more than 2mg lipid sample. Thus, to determine the appropriate lipid amounts (mg) analyzed . A constant level (41$\mu\textrm{g}$/mg) of cholesterol concentration was observed from the sample containing 0.1-1mg lipid. after which the cholesterol level was dropped to less than 41$\mu\textrm{g}$ /mg. Cholesterol concentration in egg yolk samples quantified by CTM was in accordance with that by GC method. These results suggest that CTM is an useful method for the quantification of cholesterol in egg yolk lipid and other lipids as well.

• Journal of Nutrition and Health
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• v.27 no.3
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• pp.215-227
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• 1994

Changes in total lipid content, total cholesterol content and fatty acid composition of preterm milk were investigated during early lactation. Milk samples were collected from Korean mothers of 16 premature(34 to 36 weeks gestation age) infants on day 2 to 5(colostrum) and at 6 weeks(mature) postpartum. We estimated the lipid nutrition of preterm milk by comparing with the lipids of term milk. The total lipid content of preterm colostrum was significantly lower than the lipid content of preterm mature milk(p<0.001). Lipid content, determined gravimetrically in colostrum and matured milk, was 1.50g/이 and 3.2g/dl, respectively. Also the total cholesterol content(mg/dl) in preterm milk tends to increase from 14.16mg/dl to 15.20mg/dl, while the total cholesterol(mg/g lipid) concentration higher significantly in colostrum(12.36mg/g) than in mature(5.73mg/g)(p<0.001). The total unsaturated fatty acid contents in preterm milk were higher in colostrum than in mature milk and the total saturated fatty acids were higher in mature milk. The average DHA contents of colostrum and matured milk was 0.64%, 0.53% and the P/M/S ratio of preterm milk were 0.63 : 1.05 : 1.00, 0.47 : 0.79 : 1.00, respectively. Also, $\omega$6/$\omega$3 ratio of preterm milk were 2.35 in colostrum and 5.81 in mature. Therefore, colostrum in preterm milk contained higher amounts of $\omega$3 PUFA than mature milk. The levels of total lipid in preterm milk were higher than term milk. Also, preterm milk is richer in cholesterol, and long chain polyunsaturated fatty acid than term. It appears that the milk secreted by mothers who delivered prematurely differs from milk in several important respect. These components may serve as precursors for membrane, myelin development in the preterm infants. Therefore, it would be necessary to study further into the machanism of how the gestation age might affect to the lipid composition in human milk. These data may provide a basis for better construction of infant formaulas to provide more adequately for the lipid requirements of the Korean premature infant.

• Applied Biological Chemistry
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• v.25 no.4
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• pp.239-247
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• 1982

Free and bound lipids of both inner and outer part in the edible portion of 3 varieties of chestnuts(Castanea crenata) were extracted and fractionated into neutral lipid, glycolipid and phospholipid, by silicic acid column chromatography. Fatty acid composition of each fraction was examined with gas chromatography. Lipid contents in chestnut on dry weight basis were 1.84% in inner part(1.26%-free lipid and 0. 58% bound lipid) and 1.95% in outer part (1.63%-free lipid and 0.32%-bound lipid). Free lipid content was $2{\sim}5$ times higher than bound lipid content and was more abundant in the outer part. Neutral lipid content of the free lipid in the inner part was 39.5%, approximately 10 times as much as that of the bound lipid, but in the outer part, the former was 56.6%. Glycolipid content was 22. 0% in the free lipid and 17.0% in the bound lipid. Phospholipid content was 6.9% in the free lipid and 10.5% in the bound lipid. The predominant fatty acids were linoleic acid, palmitic acid and linolenic acid in the free lipid, and palmitic acid, linoleic arid and linolenic acid in the bound lipid, Therefore, saturated fatty acid content in the bound lipid was 2 times higher than in the free lipid.

• Journal of Life Science
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• v.8 no.3
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• pp.305-311
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• 1998

These studies were undertaken to investigate changes of neutral lipid content and fatty acid composition were determined. Also accumulation process of monoglyceride, diglyceride and triglyceride content, and fatty acid composition were investigated during the development. The results were summarized as follows ; Changes of lipid during development sesame seeds, glycolipid contents which showed the highest in the early ripening stage and after that rapidly decreased, and phospholipid contents showed a similar pattern as glycolipid occurred. In contrast, the content of neutral lipid was rapidly increased by 29.21% 10 days after flowering(DAF), and showed the highest value by 91.84% at 40th day after flower. The neutral lipid, triglyceride content was rapidly increased as the seeds developed, and consisted of over 60% of the neutral lipid since 30 DAF. In the changes of neutral lipid, phospholipid and glycolipid, stearic acid and palmitic acid decreased during the seed ripening. However, oleic acid and linoleic acid increased during the same periods. Linolenic acid, which showed relatively higher value in the early ripening stage, but rapidly decreased as much as 1% at the later ripening stage.

• Journal of Nutrition and Health
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• v.27 no.10
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• pp.996-1006
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• 1994

This study was performed to investigate the effect of dietary chitin & chitosan on cadmium (Cd) toxicity and lipid metabolism in rats. Forty-two male rats of Sprague-Dawley strain weighing 137$\pm$2g were blocked into 6 groups according to body weight, and were raised for 4 weeks. Cadmium chloride was given at the level of 0 or 400ppm in diet and chitin and chitosan were given at the level of 0 or 4%(w/w) of diet. The results are summarized as follow. Chitosan decreased the toxicity of Cd on liver, kidney and femur and increase the Cd content of fecal excretion. Chitosan increased the lipdi & cholesterol content of fecal excretion by combining with lipid and bile acid. Chitosan decreased lipid, cholesterol and TG content in serum and liver by combining with lipid and bile acid. Chitin was less effective than chitosan in decreasing of Cd toxicity and lipid content of rat.

• Journal of the Korean Home Economics Association
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• v.18 no.4
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• pp.103-107
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• 1980

This study was conducted to compare the effect of dietary sucrose and starch on the lipid metabolism of Rat fed by low protein diet for 3 and 6 weeks periods. Forty male weanling Spargue-Dawley rats weighing 52.7 grams each, after being adopted for 2 days with standard diet, were blocked into 8 groups and fed experimental diet as designed. Experimental diet were composed of two different levels of proteins, 6% designed as low protein diet and 15% designed as standard protein diet. In each group, the content of serum lipid, serum cholesterol and liver lipid were measured. The results of this experiment were summerized as follows. 1. liver lipid content was tended to be high in the sucrose group of low protein fed animal. 2. the content of total serum lipid was tended to be high in the sucrose group, and this tendency was showed statistical significance in the animals fed by low and standard protein after 6 weeks of experimental period. 3. The difference in the total serum cholesterol content between the sucrose and starch group was not significant

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.6
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• pp.636-640
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• 1990

For a studyon the production of ${\gamma}$-linolenic acid(GLA) by fungi 3 fungal strains were isolated from soil. Their cell growth lipid content and fatty acid composition were compared in shake flask culture. Among these fungi the fungus designated as FA-007 has high lipid content(21.1%) and GLA content(15.6% of total fatty acids) The fungal strain FA-007 was tentatively identified as Mucor sp. on the basis of morphological characteristics, Fungal oil produced by this fungus was composed of 75.2% neutral lipid 5.3% glycolipid and 19.5% phospholipid. Although the GLA content in phospholipid was higher than it in neutral lipid the GLA content in neurtal lipid was high as 15.5%.

• Microbiology and Biotechnology Letters
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• v.27 no.2
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• pp.153-158
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• 1999

This study was conducted to investigate the production of lipid, and removal of nitrogen and phosphorus from swine wastewater by Botryococcus braunii UTEX 572 in a tubular bioreactor. The rate of dry cell weight increase of B. braunii was highest at 20.1mg/l/din a modified Chu 13 medium at $25^{\circ}C$. Under the above conditions, the rate of lipid content increase was also highest at 6.1mg/l/d. The lipid content of B. braunii on a dry weight basis ranged from 30.5 to 34.1% with an average value of 32.3%. When B. braunii was cultured in a secondary-treated swine wastewater diluted to 50% with tap water, the rate of dry cell weight increase was 18.6mg/l/d and the rate of lipid content increase was 6.0mg/l/d. The lipid content ranged from 30.3 to 34.2%. No significant difference was observed between lipid content and growth conditions. The removal rates of nitrogen and phosphorus in swine wastewater were 43.9% and 41.7%, respectively, after 14 days of incubation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.6
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• pp.641-645
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• 1990

In order to study the influence of culture conditions on cell growth and lipid formation by Mucor sp, various carbon and nitrogen sources initial pH and C./N ratio of medium were investigated. Glucose was found to be suitable carbon source in terms of lipid yield and ${\gamma}$-linolenic acid(GLA) content. When NH4Cl and (NH4)2SO4 were used as nitrogen source lipid content was high(19-21%) but GLA content was low(15-17%) On the other hand when NaNO3 and KNO3 were used lipid content was low(about 13%) but GLA content was high(22-23%). The highest production of lipid was obtained at a C/N ratio of 40 using glucose and (NH4)2SO4 as carbon and nitrogen source respectively. it was found that lipid yield was high at pH4.6 Also this fungus did not grow at 35$^{\circ}C$ and lipid yield was highr at 15$^{\circ}C$ than $25^{\circ}C$.

• Journal of Ginseng Research
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• v.5 no.1
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• pp.41-48
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• 1981

Total saponin, protopanaxadiol-saponin and protopanaxatriol-saponin were isolated and purified from the side roots of red ginseng. After we administered them orally into rats during 5 weeks, we observed their effects on lipid and glucose content in rat serum. The change in body weight of protopanaxatriol- saponin treated group was slightly larger than those of other groups. Total lipid content in total saponin treated group showed an increase of about 20 % over that in control group. However, protopanaxadiol-saponin and protopanaxatriol- saponin treated groups showed no change. While triglyceride content in total saponin treated group decreased 29oyo compared to it s content in control group, its content in protopanaxatriol-saponin treated group increased 45%. Three saponin treated groups showed lower value than control group in total ant free cholesterol levels. While glucose content in total saponin treated group decreased slightly, that in Protopanaxadiol-saponin treated group decreased slightly compared to that in control group. And protopanaxatriol- saponin trented group showed the significant decrease of 25%. From these results, it is supposed that total saponin accelerates the conversion of lipid into glucose and that protopanaxatriol- saponin accelerates the conversion of glucose into lipid.