• 한국식품조리과학회지
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• 제23권6호
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• pp.810-817
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• 2007

The quality properties of Jeung-pyun made with soybean protein isolate(SPI) were investigated. The SPI Jeung-pyun was manufactured using 3% whole protein, 7S protein or 11S protein(w/w). The redness values (a-values) of the Jeung-pyun were negative and the yellowness(b-value) of the control group was significantly lower compared to the other samples. The textural characteristics of the Jeung-pyun were influenced by the additions of SPI. The Jeung-pyuns containing soybean flour, whole protein, 7S and 11S protein had increases in springiness, but decreases in cohesiveness. In the sensory evaluation, overall desirability, sweetness, and moistness were highest in the whole protein group. The control group showed the highest scores for hardness and toughness, and the scores for after-taste and adhesiveness were the highest in the samples made with soybean flour. The 7S and 11S additions showed high scores in terms of color and springiness. In the analyses for consumer acceptance and sensory quality intensity, the whole protein addition had significantly higher scores for general acceptability and the Makgeolli flavor. Hardness was highest for the control group and the Makgeolli flavor was strongest with the soybean flour addition.

• 한국식생활문화학회지
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• 제14권5호
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• pp.467-476
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• 1999

We studied to improve the functional properties of soybean protein isolate by dimethylglutarylation and acetylation. Soybean protein isolate was acylated rapidly up to 80% modification and more of 80% modification was proceed slowly. Electrophoretic analysis showed that more changes in modified protein. Also, modification of soybean protein produced more ionizable tyrosines and exposed more hydrophobic groups, while modified protein exhibited a loss of reactive sulfhydryl groups. Spectrophoretic studies demonstrated that the shift was occurred at the UV 278nm and fluorescence 333nm, respectively, and the intensity decreased as the degree of modification was increased.

• 한국식품과학회지
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• 제24권3호
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• pp.294-299
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• 1992

본 연구에서는 분리대두단백질에 단백질 가수분해효소를 처리하여 대두단백질에 가수분해적 변성을 야기하여 그 기능성을 변화 고찰하고 실제 식품에의 이용방법으로 효소처리된 두유로 두부를 만들어 물성실험과 관능평가를 실시하였다. 장엽에서 SPI를 제조한 후 15분간 bromelain으로 처리하여 2.7% 가수분해된 MSPI를 만들어 기능특성을 측정 비교하였다. MSPI는 전 pH범위에서 용해도가 증가하였고, 특히 등전점에서 15% 정도 증가하였다. 유화형성력과 기포팽창력은 증가하였으나 이들의 안정성은 감소하였는데, 특히 기포안정성은 알칼리쪽에서 급격히 감소하였고, 등전점에서는 가장 큰 것으로 나타났다. 표준두유와 변형두유를 혼합하여 제조한 두부로 물성실험과 관능평가를 실시하였을 때 압착실험에서는 변형두부I이 연하고 탄력성 있는 두부를 형성하는 것으로 나타났다. 각 두부의 물성모형은 spring 한개와 Maxwell 모형 세개를 가진 7요소모형으로 동일한 물성모형을 나타내었다. 관능평가에서는 표준두유와 변형두유를 3 : 1의 비율로 혼합하여 제조한 두부의 품질이 가장 우수한 것으로 평가되었다.

• 한국식품영양과학회지
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• 제39권1호
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• pp.8-13
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• 2010

분리대두단백질의 가수분해물을 제조 시, 최적 가수분해 조건을 설정하기 위하여 총 7종의 단백질 가수분해 효소를 이용하여 효소선정, 효소농도, 가수분해시간 및 분리대두단백질분말의 첨가량에 따른 단백질의 함량 정도를 나타내는 280 nm의 흡광도 측정과 수율을 대신한 brix 측정, 가수분해물의 ACE 저해활성 등을 조사하였다. 분리대두단백질 분말에 증류수를 5%의 분산농도로 하여 분해효소 Alcalase 2.4 L을 1%(v/w) 첨가하여 $65^{\circ}C$에서 4시간 동안 가열하여 가수분해하였다. 가수분해를 마친 후 효소의 반응정지를 위하여 $80^{\circ}C$에서 5분간 열처리한 후, $4^{\circ}C$로 냉각하여 원심분리(7,000 rpm, 40 min) 하였다. 원심분리 한 상등액을 취하여 여과한 후, $60^{\circ}C$에서 농축하였다. 농축액을 냉동시켜, 진공 동결건조 하여 분리대두단백질 가수분해물을 제조하였다. 분리대두단백질 가수분해물의 수율은 38.32%를 나타냈으며, ACE 저해활성($IC_{50}$)은 $79.94 {\mu}g/mL$를 나타내었다.

• 한국식품과학회지
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• 제2권2호
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• pp.49-55
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• 1970

대두단백육(textured soybean protein food)의 제조 과정에서 분리한 대두단백의 건조공정은 단백 gel의 성질과 보수력, 점성도 같은 단백질 특성에 영향을 미쳤다. 모델시스템의 실험에서 질소용해계수로 표시한 대두단백의 변성도는 분리대두단백 gel의 강도의 중요한 변수로 나타났다. gel strength는 질소용해계수가 43이었을 때 최대가 되었고 질소 용해계수가 그보다 증가할 때나 감소할 때는 gel strength가 감소되었다. 이러한 사실은 분리대두단백의 건조공정 중 적당한 단백의 변성은 단백육제조에 필요하며 그 이상의 높은 질소용해계수를 갖도록 할 필요는 없다.

• 한국식생활문화학회지
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• 제14권5호
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• pp.477-485
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• 1999

This study was conducted to improve the functional properties of soybean protein isolate by dimethylglutarylation and acetylation. Amino acid composition and solubility of modified soybean protein by dimethylglutarylation were not changed, but lysine and trypsin inhibitor activity was decreased an isoelectric point was moved from pH5 to pH4 as a result of modification. Emulsification capacity and stability, foaming capacity and thermal stability were increased by the modification. In that 91% dimethylglutarylated protein did not coagulate when heating at $100^{\circ}C$ for 20 min. while its foaming stability was decreased. Whereas specific gravity was decreased by the modification of the soybean protein, relative viscosity and whiteness were improved. Generally, dimethylglutarylation produced more conformational changes in protein system than did in acetylation.

• Food Science and Biotechnology
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• 제18권2호
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• pp.488-493
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• 2009

A protein isolate was prepared from black soybean (Glycine max L. Merrill) that possessed higher antioxidant activity than ordinary white soy protein isolates. The isolate was partially hydrolyzed by alcalase to reduce the allergenicity of black soybean. Alcalase remarkably reduced the molecular mass of the major soybean allergens that have molecular weights of 53, 38, and 24 kDa. Hydrolytic breakdown occurred more effectively in Gly m Bd 30K than in Gly m Bd 60K or Gly m Bd 28K. Alcalase hydrolysis increased the solubility and hydrophobicity of the black soybean protein isolate. The foaming activity and stability of black soybean proteins were highly increased by the partial hydrolysis.

• Journal of Korean Biological Nursing Science
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• 제10권1호
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• pp.1-10
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• 2008

Purpose: The purpose of this study was to investigate the cerebral infarction size, antioxidant enzyme activities and lipid peroxidation changes after 6 weeks of dietary soybean protein intake in a rat focal brain ischemia model. Method: Weaning Sprague-Dawley rats were fed with either modified AIN-93G diet containing casein 20% (control), 20% soybean protein isolate-based diet (S20), or 40% of soybean protein isolate-based diet (S40) for 6 weeks. The animals were subject to right middle cerebral artery occlusion for 2 hr. After 24 hr of recirculation, the rats were sacrificed. Antioxidant enzymes activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) and thiobarbituric acid reactive substance (TBARS) level in the right brain were also measured. Result: There were no significant differences in the right cortical infarction volume, TBARS level, SOD and CAT activities among the three groups whereas the GPx activities of the S20 group were significantly higher than those of the control group (p=.02). Conclusion: Our results suggest that 20% of soybean protein may have a modulating effect on GPx and possibly have some protective effect against oxidative stress although it may enough to decrease cerebral infarction volume in rat focal brain ischemia model.

• 한국식품조리과학회지
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• 제24권3호
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• pp.304-311
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• 2008

This study examined Jeung-pyun(JP) Retrogradation in samples containing 3% whole protein, 7S protein, or 11S protein(w/w) that were stored at $4^{\circ}C$ for 6, 12, 24 and 72 hr. Rheometery and differential scanning calorimetry(DSC) were used in the analysis. The pH of the dough decreased during the fermentation process, but it increased after steaming. The JP prepared with soybean protein isolate(SPI) had higher pH than the control group. During storage the textural characteristics of the JP showed effects according to the additions of SPI. After 6 hr of storage, the JP samples containing soybean flour, whole protein, 7S protein, and 11S protein had lower hardness valuse. From 4 hr to 12 hr, higher springiness values were found in the samples containing whole protein, 7S protein and 11S protein. At 0 hr, the control group had the highest cohesiveness value, but after 24 hr it presented the lowest value. For gumminess, after 6 hr of storage, the control group offered the lowest value. Whereas after 12 hr of storage the whole protein group showed the highest value, and at 24 hr, the whole protein, 7S protein, and 11S protein groups had higher values. According to the DSC results, the 11S protein group had lower enthalpy values(${\bigtriangleup}H$) suggesting that adding 11S protein to JP might improve starch retrogradation. After 72 hr of storage, the control group had the highest onset temperature($T_{o}$) and peak temperature($T_{p}$) whereas the 7S and 11S protein JP samples had higher conclusion temperatures($T_{c}$). Therefore, based on the different analysis result between the control and treatment groups, the addition of SPI to Jp had effects on retrogradation.

• Journal of Nutrition and Health
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• 제38권4호
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• pp.279-288
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• 2005

The purpose of this study was to examine whether soybean protein isolate with rich isoflavones which was the same amount as used for earlier study prevents bone induced by ovarian hormone deficiency. Forty female Sprague-Dawley rats (body weight 210 $\pm$ 5 g) were divided into two groups, ovariectomy (OVX) and sham surgery groups, which were each randomly divided into two subgroups that were fed casein and soybean protein isolate with rich isoflavones (isoflavones 3_4 mg/g protein). The diets were fed for 9 weeks after operation. The results of this study indicate that body weight gain and food intake were higher in OVX groups than in SHAM groups regardless of diets. Weight gain were higher in soy isolate groups than in casein groups. Serum Ca concentration was lower in OVX rats than in SHAM rats when fed casein diet. Within the OVX groups, serum Ca concentration was higher in rats fed soy isolate diet than in rats fed casein diet. Serum ALP were higher in OVX groups than in SHAM groups. Within the OVX, soy isolate groups, indices of serum osteocalcin, were a trend for greater than those of the OVX casein group. Crosslink value were increased in ovariectomy groups. Spine BMD and femur BMD of ovariectomy groups were significantly lower than SHAM groups. However, soy isolate with rich isoflavones group in ovariectomy groups, spine BMC and femur BMC were significantly increased after 9 weeks. In conclusion, the soy protein with rich isoflavones was beneficial for bone in ovareiectomized rats and the results were similar to the findings of our previous study which showed a beneficial effect on bone in growing rats.