• Korean Chemical Engineering Research
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• 제43권2호
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• pp.236-242
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• 2005

대표적인 단백질 물질인 bovine serum albumin(BSA), lysozyme, pepsin, casein 그리고 ovalbumin의 이성분계 단백질 혼합물의 미세 분리 막에서 보이는 막 오염 현상에 관한 실험을 고찰하였다. 트랙 에치법에 의해 제조된 $0.2{\mu}m$ 폴리카보네이트 미세 막을 이용하여 단백질 혼합물 용액의 조성과 종류가 여과유량감속에 미치는 영향에 대한 실험을 일정한 압력(14 kPa)과 수소이온농도(pH=11) 하에서 수행하였다. 각각의 이성분 단백질 혼합물에 대한 막오염 현상을 확인하였으며, 유량 감속 데이터는 최근에 개발된 pore blockage-cake formation 모델을 이용하여 분석한 결과, 실험 결과와 일치하였다. 이성분계 단백질 혼합물의 조성과 단백질 종류가 막오염 및 유속변화에 미치는 영향은 공극막힘속도(${\alpha}$), 단백질 침적층의 초기 저항($R_{po}$) 및 단백질 저항의 증가속도(${\beta}$)에 의해 설명 할 수 있었다. 대체로 공극막힘속도의 변화는 유속감소현상과 일치함을 알 수 있으며, 특히 casein이 존재하는 단백질 혼합물에서의 급격한 유량감속은 casein에 의한 단백질 침적층의 초기저항에 크게 기인된 것으로 판단된다.

• Journal of Nutrition and Health
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• 제8권3호
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• pp.19-29
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• 1975

This study was designed to compare the metabolic effects of varicous types of Korean diet. 40 males and same number of females of Albino rats, divided into eight groups, 5 rats each. 1 Group; Sugar casein standard Group 2 Group; Rice casein standard Group 3 Group; Rice group 4 Group; 65% Rice +35% Anchovy 5 Group; 65% Rice +35% Chinese cabbage 6 Group; 65% Rice+10% Anchovy +25% Chinese cabbage 7 Group; 65%. Rice+26% Chinese cabbage+3.5% Anchovy+4% Bean+1% Potatoes+0.2% Sea Weeds+0.3% Seasonings 8 Group; 47% Rice+24% Chinese cabbage+20.5% Anchovy+5% Bean+1% Potatoes+1.8% Sea Weeds+0.7% Seasonings The rats were kept in individual cage and given 8 different diet for 10 weeks. The result of this study were elucidated as fallow. Food intake of sugar casein standard group and rice casein standard group and Seoul diet pattern group were high, Rice diet group showed low food intake. F.E.R, P.E.R, body weight, organ weight were the similar results. The nitrogen content in various organs were no great difference, but nitrogen metabolism and total nitrogen retention were significant differences. The lipid content in the liver showed no significant differences, but fecal lipid and serum cholesterol showed significant differences. This study showed the glucose content in urine and feces were due to the dietary carbohydrate content. In other word, the results of this study showed no significant differences between sugar casein standard group and rice casein standard group, but significiant differences between standard group and experimental group.

• Journal of Nutrition and Health
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• 제17권1호
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• pp.20-30
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• 1984

This experiment was designed to investigate the effects of the mixing ratio of soyprotein and casein, and the level of pectin combined with the mixture on lipid metabolism in rats. Forty-eight male weanling rats of Wistar strain weighing 58.8\;{\pm}\;1.9g$ were divided into six groups by completely randomized block design and fed 10% protein diet for four weeks. Two types of protein mixtures (casein to soyprotein mixing ratio of 1 : 3 and 2: 1)combined with 0.5% , 3%, and 5% of pectin were employed for experimental diets. The results obtained in the study are summarized as follows ; 1) Feed efficiency ratio and protein efficiency ratio were not significantly different among six groups for the whole experimental period, but those for high casein-low pectin group were significantly higher than the ones for high soy-high pectin group at 4th week of the experimental period. 2) Gross fecal dried weight and fecal lipid excretion were higher in high pectin groups of both protein combinations. Therefore, the apparent fat digestibility and absorption appeared to be significantly low in high pectin groups. 3) Pectin was effective in lowering serum lipid and cholesterol levels in high casein groups, but no effect of pectin was noted in high soyprotein groups. 4) Lipid and cholesterol contents of the liver were higher in high soy-low pectin group than the others. And no marked differences in lipid and cholesterol contents in the kidney and carcass were observed.

• 동아시아식생활학회지
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• 제7권1호
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• pp.13-20
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• 1997

This study was designed to determine the effects of protein sources on the curation of gastric ulceration, protein metabolism, and nitrogen balance in rats with gastric ulcer induce by restraint and water immersion stress. After the rats were fed 10% casein diet for 3 weeks, four groups of the rats were forced in 5$\times$5$\times$15cm plexiglass cage. The restraint and water immersion stress was carried at 20$\pm$2$^{\circ}C$ for 8-hour. The other one group(control group) was not exposed to stress. After stress 4 kinds of different diets containing 20% protein were given for 5 days. The protein sources were casein, whey protein, soy protein, gluten. The control group was fed to 10% casein diet. The results were as follows ; the weights of rats were not different among the diet groups During the experiment period follows ; the weights of rats were not different among the diet groups during the experiment period (for 5 days). The ulcer index of rats fed 10% gluten and soy protein diet was significantly higher than those of casein and whey protein diet groups(p<0.05). The level of serum albumin was not significantly different among diet groups. But hematocrit and the level of $\alpha$-amino-N, BU and UUN of plant protein diet groups were higher than animal diet groups, the urinary hydroxyproline of soy protein group was the highest and the whey protein was the lowest. The digestibility and BV of nitrogen of gluten diet group were significantly higher than those of casein and whey protein diet groups(p<0.05). The animal proteins had more curative effects of ulcer than plant animals. The results of this study provide useful information concerning diet therapy for the patients with gastrointestinal diseases and the field of enteral diet materials.

• Journal of Nutrition and Health
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• 제39권3호
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• pp.236-243
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• 2006

A recent study reported that a diet rich in isoflavones is beneficial for bone formation in growing rats. It therefore seemed desirable to find out whether the beneficial effect of isoflavones in ovariectomized rats could also be reproduced with same amount of isoflavones which used for growing rats. To study the effect of isoflavones, an equal amount of isoflavones which used for growing rats, on bone mineral density and bone mineral content in ovariectmized rats were performed. Forty female Sprague-Dawley rats (body weight $210{\pm}5g$) were divided into two groups, ovariectomy and sham groups, which were each randomly divided into two subgroups that were fed casein and casein supplemented with isoflavones diets for 9 weeks after operation. All rats were fed on experimental diet and deionized water ad libitum for 9 weeks. Bone mineral density (BMD) and bone mineral content (BMC) were measured using PIXImus (GE Lunar Co, Wisconsin) in spine and femur. Serum alkaline phosphatase activity (ALP) and osteocalcin and urinary DPD crosslinks value were measured as markers of bone formation and resorption. The results of this study indicate that body weight gain and food intake were higher in ovariectomy groups than in sham groups regardless of diets. Serum Ca concentration was lower in ovariectomy groups than in SHAM groups. Serum ALP, osteocalcin, and crosslink value were increased in ovariectomy groups. Spine BMD/weight, femur BMD/weight, and femur BMC/weight of ovariectomy groups were significantly lower than SHAM groups after 9 weeks. However, isoflavones supplemented group in ovariectomy groups, serum ALP and osteocalcin concentrations, spine BMD/weight and spine BMC, femur BMD/weight and femur BMC/weight were significantly increased after 9 weeks. In conclusion, the beneficial effect of isoflavones on bone in ovareiectomized rats was shown on 9 weeks after feeding with an equal amount of isoflavones supplementation which used for growing rats.

• Journal of Nutrition and Health
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• 제36권4호
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• pp.359-367
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• 2003

The purpose of this study was to examine the impact of soy protein and soy isoflavones on bone and mineral density in young female Sprague-Dawley rats. Fifty eight rats (body Weight 75 $\pm$ 5 g) were randomly assigned to one of four groups, consuming casein, soy protein concentrate, soy protein isolate (57 mg isoflavones/100 g diet) or casein added isoflavones (57 mg isoflavones /100 g diet). All rats were fed on experimental diet and deionized water ad libitum for 9 weeks. Bone mineral density (BMD) and bone mineral content (BMC) were measured using PIXImus (GE Lunar Co, Wisconsin, USA) in spine and femur on 3, 6, 9 weeks after feeding. The serum and urine concentrations of Ca and P were determined. Diet did not affect weight gain and mean food intake. Food efficiency ratio was lower In soy protein groups. The serum concentration of Ca and P were not changed by soy protein and isoflavones. Urinary Ca and P excretion were not significantly different. Spine BMD was significantly increased by soy protein isolate on 3 and 6 weeks after feeding. Femur BMD was significantly increased in the groups of soy protein isolate and isoflavones adding on after 9 weeks. Therefore, soy protein with rich isoflavones may be beneficial on spine and femur BMD increasement in growing female rats.

• 대한약리학회지
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• 제7권1호
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• pp.37-52
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• 1971

It has been demonstrated repeatedly that the administration of ethionine, a methionine analogue, will produce destruction of pancreatic tissue and liver cells. Destruction of acinar cells of pancreas by the administration of excess methionine similar to that seen after feeding diets supplemented with ethionine was also reported, but the liver was not involved by this amino acid. In an attempt to reproduce the results of these investigators the tissue damages were found to be slight and seen only irregulary in rats receiving ethionine on a complete diet and the result of tissue damages by excess methionine were also controversial. The present studies describe the toxicity of dietary supplemented ethionine and methionine to liver and pancreas in rats fed a low protein diet. Hundred five albino rats weighing around 120 gm were divided into three groups as follows; 1) Control group: A low protein diet containing 8% casein was fed throughout the experimental period. 2) Methionine group: A low protein diet (7% casein) supplemented with 1% methionine was used. 3) Ethionine group: A similar diet as methionine group except the supplementation of 1% ethionine instead of methionine was used. Five animals per wee from each group were killed for 6 weeks. The liver and pancreas were fixed in 10% formalin and histologic sections were prepared and stained with hematoxylin eosin. Serum amylase was expressed as much of glucose liberated from a starch substrate. The glucose was determined by the method of Nelson (1944). Serum glutamic pyruvic transaminase (SGPT) and glutamic oxaloacetic transaminase (SGOT) were determined by the technique described in Sigma Bulletin.

• Journal of Nutrition and Health
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• 제40권3호
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• pp.235-241
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• 2007

The aim of this study was to define an arginine effect when added to a diet. The influence of arginine supplements on bone mineral density and content were studied in young female Sprague-Dawley rats fed either an arginine supplemented diet or control diet. Twenty four rats (body weight $83{\pm}5g$) were randomly assigned to one of two groups, consuming casein or casein with supplemented arginine diet. All rats were fed on experimental diet and deionized water ad libitum for 9 weeks. Bone mineral density (BMD) and bone mineral content (BMC) were measured using PIXImus (GE Lunar Co, Wisconsin, USA) in spine and femur 3, 6, and 9 weeks after feeding. The serum and urine concentrations of Ca and P were determined. Diet did not affect weight gain and mean food intake. The serum concentration of Ca and P were not changed by arginine supplementation. Urinary Ca excretion was significantly decreased by arginine supplementation. Spine BMD was significantly increased by arginine supplementation on 3 and 6 weeks after feeding. Femur BMD was significantly increased in the group of arginine supplementation on 3, 6, and 9 weeks. Rats fed the arginine-supplemented diet had better bone mineral content than did control diet rats in the experimental period. Therefore, arginine supplementation may be beneficial on spine and femur BMD increment in growing female rats. These are thought to be associated with an arginine-induced growth hormone release. The exact mechanism of this effect remains to be elucidated.

• Journal of Nutrition and Health
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• 제37권2호
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• pp.100-107
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• 2004

This study was performed to evaluate the effect of dietary protein source and sulfur amino acid content on bone metabolism in ra. Thirty male rats (body weight 145$\pm$2g) were divided into three groups. The rats in the first group were fed on casein 20% diet as animal protein source and those in the second group were fed on soy 20% diet as plant protein source. Sulfur amino acid ratio of these group was 1.07:1. The rats in the third group were fed on soy 20% diet and the sulfur amino acid were supplemented with the amount contained as much in the soy 20% diet. All rats were fed on experimental diet and deionized water ad libitum for 9 weeks, The total body, spine, femur bone mineral density and bone mineral content were measured using Dual Energy X-ray Absorptiometry Calcium, phosphate, pyridinoline, creatinine in urine and calcium, phosphate, alkaline phosphatase, osteocalcin in serum were measured. During the experimental period, plant protein (soy protein) group had a lower urinary Ca excretion, urine pyridinoline ＆ crosslinks value and had a higher Ca efficiency in total bone and femur bone mineral density than animal protein (casein) group. There were no significant differences in serum calcium, phosphate, alkaline phosphatase and osteocalcin among the three groups of the rats. The findings from this study demonstrated that plant protein (soy protein) is beneficial of bone mineral density because it had a higher Ca efficiency in total bone and femur bone mineral density than animal protein (casein). However, the supplementation of sulfur amino acid on soy results were consistent with prior studies that dietary sulfur amino acid load had a negative effect on calcium balance. The rats fed sulfur amino acid supplementation diet increased urinary calcium excretion and decreased calcium efficiency for total and femur mineral density. Therefore, dietary protein source and sulfur amino acid content influence bone metabolism. (Korean J Nutrition 37(2): 100-107, 2004)

• Nutrition Research and Practice
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• 제5권1호
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• pp.46-51
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• 2011

To evaluate the effect of feeding methods on growth and zinc nutritional status of infants early in life, we monitored from birth to 36 months in 51 infants who were exclusively fed human milk (HM, n=20), casein-based formula (CBF, n=12), or soy-based formula (SBF, n=19) during the first five months of life. Zinc status was assessed by analyzing serum zinc concentrations and zinc intakes. Zinc contents in HM and formulas were measured. Zinc intake was estimated by weighing infants before and after feeding in the HM group and by collecting formula-intake records in the CBF and SBF groups. After solid foods were introduced, all foods consumed were also included to estimate zinc intake. The growth of infants in all groups was similar to that established for normal Korean infants. Human milk zinc concentrations declined as lactation progressed. Zinc concentrations in all formulas tested in this study were higher than HM and were also higher than those claimed by the manufacturers. During the first twelve months, mean serum zinc concentrations of infants were similar in all groups, although infants in the HM group consistently had the lowest zinc intake among the groups, and the overall zinc intake in infants fed SBF was highest. This finding could be explained by the difference zinc bioavailability of HM and formulas. In conclusion, infants fed HM, CBF or SBF has normal growth up to three years of age, although HM contained the lowest zinc concentration followed by CBF, then SBF.