• 한국식품영양학회지
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• 제10권2호
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• pp.246-253
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• 1997

단백질의 종류 및 급여수준이 고콜레스테롤혈증 흰쥐의 체내 지질대사에 미치는 영향을 구명학자 1% 콜레스테롤과 0.25%의 콜산나트륨을 첨가하여 고콜레스테롤 혈증을 유도토록 조제한 실험식이에 대두단백질과 카제인의 공급수준을 달리하여 급여하고 혈청내 지질대사를 관찰하였다. 혈중 총지질 함량은 콜레스테롤 투여시 정상군에 비해 유의적으로 증가되었으며 단백질 급여로 증가가 억제되는 것으로 나타났으며 대두단백질이 더 유의적으로 억제되었다. 트리글리세라이드는 콜레스테롤 투여군이 정상군에 비해 유의적으로 증가되었으며 단백질 급여로 증가가 억제되었으며, 단백질의 종류에 따른 차이는 관찰되지 않았고 인지질 함량은 콜레스테롤 투여군이 정상군에 비해 유의적으로 감소되었다. 총 콜레스테롤 함량과 유리 콜레스테롤 함량은 정상군에 비해 골레스테롤 투여군 모두에서 유의적으로 증가되었으며, 카제인 급여군에 비해 대두단백 급여시 유의적으로 증가가 억제되는 것으로 나타났다. VLDL- 및 LDL-콜레스테롤 함량은 정상군에 비해 콜레스테롤 투여시 유의적으로 증가하였으며, 단백질 급여 수준이 증가할수록 그 증가가 억제되는 것으로 나타난 반면, HDL-콜레스테롤 함량은 콜레스테롤 투여로 인해 유의적으로 감소되었으며 대두단백질이 카제인에 비해 감소 정도가 유의적으로 억제되었다. 이상의 결과에서 단백질의 종류와 급원이 지질함량에 영향을 미치므로써 고콜레스테롤 혈증을 예방·치료하기 위하여 단백 급여, 특히 대두단백 급여가 중요한 요인으로 작용할 것을 사료된다.

• 대한가정학회지
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• 제28권4호
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• pp.41-50
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• 1990

Soy protein was isolated from Korean soy bean 'Chang ryub' and chemically modified with succinic anhydride. Functionality of the soy protein isolate(SPI), succinylated SPI(SPPI), and PP590(commercial) at various pH were investigated. The mechanical and sensory properties of soy bean curds made from several mixing ratio of succinylated soy bean milk were observed. The solubility of SPI significantly increased with succinylation. The solubility of PP590 was lower than that of SSPI. The solubility of SPPI increased significantly in 0.03M CaCl2 solution. The emulsifying activity of SSPI increased. On the range of pH above pI the emulsifying activity of PP590 was higher than that of SPI. There was no difference in emulsion stability among the groups. The foam expansion capacity of SPPI increased at higher pH than pI but the foam stability decreased significantly above pH 9. Mechanical texture profile analysis revealed the modified soy bean curds had the lower hardniss, chewiness and cohesiveness with increased modification. The mechanical characteristics of modified soy bean curds revealed generalized Maxwell Model of 7-elements or 5-elements. In sensory evaluation, the hardness, the springiness and acceptability of modified soy bean curds were lower significantly than those of control soy bean curd.

• 한국생활과학회지
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• 제7권2호
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• pp.149-159
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• 1998

This study was carried out to examine the role soy milk in the preparation of Yukwa, possibility of substitution of soy milk to isolated soy protein and the effect of drying condition of Yukwa dough on the quality of Yukwa for the purpose of standardization of Yukwa preparation process. Although isolated soy protein did not make any particular effect on the gelatinization characteristics of waxy rice flour, soy milk lowered peak viscosity to half of waxy rice flour. The optimum moisture content of dried Yukwa dough was about 25%, and it can be reached by drying at $60^{\circ}C$ under atmosphere pressure for $4{\sim}5$ hours. On the basis of the results of morphological observations, mechanical and sensory measurement of hardness, and sensory test of the internal structure, mouthfeel and overall acceptability, soy milk was more desirable than isolated soy protein for the quality improvement of yukwa.

• Journal of Applied Biological Chemistry
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• 제51권3호
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• pp.88-94
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• 2008

Three different protein extraction methods-phenol extraction, trichloroacetic acid (TCA) precipitation, and desalting/TCA precipitation-were compared to determine the optimal reproducible high resolution 2-dimensional (2-D) electrophoresis for each chungkugjang, doenjang, and kochujang samples. The soluble proteins from Chungkugjang extracted by phenol were separated with high reproducibility and resolution, and gained 1.75- to 3-fold more protein spots on 2-D gel than those from the other methods. On the contrary, the extracted proteins from doenjang and kochujang treated by desalting/TCA precipitation method showed about 1.5- to 3.3-fold more protein spots on 2-D gel. Using the established methods, the changes in the protein profiles of the fermented soy foods were monitored during the fermentation period by 2-DE. One of the major proteins in soy, $\beta$-conglycinin $\alpha$-subuint, and some proteins with unknown functions were localized on 2-D gel as the protease-resistant proteins throughout the fermentation period of doenjang. Changes in the protein profile monitored by the established methods can provide basic information on unfolding the mechanisms of the generation of biofunctional activity in the fermented soy foods.

• Asian-Australasian Journal of Animal Sciences
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• 제18권3호
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• pp.326-331
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• 2005

A rumen simulated continuous culture (RSCC) system was used to study the influence of supplementation of the three different types of protein sources such as urea, casein and soy protein on rumen microbial synthesis in terms of rumen microbial synchronization. The urea treatment showed the highest pH value. Ammonia nitrogen concentration was rapidly increased after feeding and not significantly different in the urea treatment (13.53 mg/100 ml). Protozoa numbers were not significantly different for soy protein and casein treatment compared to urea treatments during incubation. The average concentration of total VFA (mMol) was not detected with significant difference among treatments, but iso-butyrate production showed the highest for soy protein treatment among treatments (p<0.001). The lowest concentration in total iso-acids (iso-butyrate and iso-valerate) production was observed in urea treatment. The soy protein treatment showed no significantly change in acetate/propionate. The amounts of dry matter (DM) out flow showed no significant difference among treatments. Organic matter (OM) flow was the highest for urea treatments and the lowest for casein treatment (p<0.03). The nitrogen flow for casein treatment was not significantly different from other treatments. The efficiency of microbial protein synthesis in terms of microbial nitrogen (MN) synthesis (g MN/kg ADOM) digested in the rumen was highest for casein treatment (58.53 g MN/kg ADOM) compared to soy protein and urea (p<0.05). This result suggests that rumen ammonia releasing rate may influence on microbial protein synthesis in the rumen.

• 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)

• 한국식품과학회지
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• 제21권1호
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• pp.92-99
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• 1989

본 연구에서는 농축대두단백으로 두유를 만들고 protease를 이용하여 대두단백질을 여러가지 정도로 가수분해한 후, 단백질이 일부 가수분해된 두유에서 L. acidophilus 또는 L. bulgaricus의 생육과 산생성을 관찰하고 제조된 대두 젖산균음료의 관능성을 조사하였다. protease 처리에 의하여 젖산균에 의한 산생성이 촉진되었는데 특히 L. acidophilus에 의한 산생성이 현저하게 촉진되었다. 그러나 pH와 생균수는 큰 변화가 없었다. 15분 가수분해 시료에서 이미 산도가 상당히 증가하였으며 그 후 3시간이 경과하여도 산도의 변화가 현저하지 않았다. 0.1% protease 처리로 대두젖산균음료의 전체적인 기호도가 다소 개선되었다. protease 처리 15분에 비단백태 질소의 함량이 상당히 증가하였고 2시간에 최대치에 도달하였다.

• Journal of Nutrition and Health
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• 제34권8호
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• pp.833-842
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• 2001

The purpose of this study is to determine the effect of dietary proteins and fats on the hepatic histological changes, membrane stability, and drug-metabolizing enzyme activities during chemically induced rat hepatocarcinogenesis. Weanling Sprague-Dawley rats were fed the diet containing 20% casein or soy protein isolate and 15% perilla or corn oil for 10 weeks. Hepatocarcinogensis was initiated with diethylnitrosamine(DEN), and the rats were fed diets containing 0.02% 2-acetylaminofluorene(AAF) followed by 0.05% phenobarbital (PB). The scores of histological changes were decreased in treated rats fed soy protein diet compared to those find casein diet. Liver weights were significantly increased by AAF and PB treatment in rats fed casein diets in both oil groups. Glucose 6-phosphatase(G6Pase) activities, an index of membrane stability, were significantly reduced by AAF and PB treatment in rats find casein diets, and were lower in casein diet compared to soy protein diet groups. Especially, the activities were the highest in the rats fed soy protein-perilla oil diet. Lipid peroxide values also were increased by AAF and PB treatment in rats fed casein diet. Aniline hydroxylase activities were not influenced by protein and fat sources. Glutathione-dependent enzyme activities were increased by AAF and PB treatment. Linoleic and arachidonic acid content were increased in rats fed corn oil diet, and linolenic and eicosapentaenoic acid contents were increased in rats fed perilla oil diet. Our results suggest that soy protein isolate inhibit the abnormal histological changes in liver, possibly by maintaining the membrane stability during chemically induced rat hepatocarcinogenesis. Soy protein may be protective against the hepatocarcinogenesis induced by chemical carcinogen.

• 한국식품과학회지
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• 제26권5호
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• pp.603-608
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• 1994

대두식품의 가공 및 발효에 따른 phytate 함량의 변화, 그 함량이 pepsin과 pancreatin에 의한 단백질 소화에 미치는 영향, 그리고 전기영동법에 의한 단백질 분획의 변화를 조사하였다. 황색콩의 phytate 함량은 2.4%이었고 가공 및 발효에 따라 감소하여 두유 0.2%, 두부 0.7%, 비지 0.4%로, 청국장 0.9%, 메주 1.4%, 간장 0.2%, 된장 1.0%로 나타났다. Phytate/protein 비율은 pepsin에 의한 단백질 소화율과 상관성이 없었으나 pancreatin에 의한 단백질 소화율과는 부(負)의 상관관계를 나타냈다(p<0.01, r= -0.73). 전기영동 결과 콩을 물에 불리면 수용성 분획이 변화되었고 두유 제조시 비지에는 주로 저분자량 밴드들이 새로이 나타났다. 발효 과정에서는 단백질이 분해되어 밴드가 거의 나타나지 않았다.

• 한국식품조리과학회지
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• 제20권3호
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• pp.256-264
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• 2004

The effects of irradiation on the functional and structural characteristics of soy protein isolates were studied. Soymilk was irradiated at 1, 5, and l0kGy, after which soy protein isolates were prepared. The functional properties of soy protein isolates were examined including solubility, emulsion capacity and stability, foam capacity and stability, structural properties as represented by SDS-PAGE pattern, and secondary and tertiary structures. The solubility and emulsion capacity were increased by radiation treatment at 1kGy however the values were adversely affected again as dosage was increased above 5kGy. As irradiation dosage increased, an increase of foaming capacity at 1kGy and a decreasing turnover afterwards were also noted in foaming capacity, although the differences were not statistically significant. The SDS-PAGE pattern showed fragmentation and aggregation of protein molecules as affected by irradiation in proportion to the dosage increase. The results of CD and fluorescence spectroscopy revealed increased aperiodic structure contents with the dosage increase. It was assumed that irradiation dosagefrom 5 to l0kGy could initiate minimal denaturation of protein in various foods compared to general heat treatment.